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Search: a256890 -id:a256890
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Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 3*x + 2.
+10
14
1, 2, 2, 4, 20, 4, 8, 132, 132, 8, 16, 748, 2112, 748, 16, 32, 3964, 25124, 25124, 3964, 32, 64, 20364, 256488, 552728, 256488, 20364, 64, 128, 103100, 2398092, 9670840, 9670840, 2398092, 103100, 128, 256, 518444, 21246736, 147146804, 270783520, 147146804, 21246736, 518444, 256
OFFSET
0,2
FORMULA
T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 3*x + 2.
Sum_{k=0..n} T(n, k) = A007559(n).
T(n, k) = (a*k + b)*T(n-1, k) + (a*(n-k) + b)*T(n-1, k-1), with T(n, 0) = 1, a = 3, and b = 2. - G. C. Greubel, Mar 20 2022
EXAMPLE
Triangle begins as:
1;
2, 2;
4, 20, 4;
8, 132, 132, 8;
16, 748, 2112, 748, 16;
32, 3964, 25124, 25124, 3964, 32;
64, 20364, 256488, 552728, 256488, 20364, 64;
128, 103100, 2398092, 9670840, 9670840, 2398092, 103100, 128;
256, 518444, 21246736, 147146804, 270783520, 147146804, 21246736, 518444, 256;
MATHEMATICA
T[n_, k_, a_, b_]:= T[n, k, a, b]= If[k<0 || k>n, 0, If[n==0, 1, (a*(n-k)+b)*T[n-1, k-1, a, b] + (a*k+b)*T[n-1, k, a, b]]];
Table[T[n, k, 3, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 20 2022 *)
PROG
(Sage)
def T(n, k, a, b): # A257610
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b)
flatten([[T(n, k, 3, 2) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 20 2022
CROSSREFS
See similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 03 2015
STATUS
approved
Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 2*x + 2.
+10
13
1, 2, 2, 4, 16, 4, 8, 88, 88, 8, 16, 416, 1056, 416, 16, 32, 1824, 9664, 9664, 1824, 32, 64, 7680, 76224, 154624, 76224, 7680, 64, 128, 31616, 549504, 1999232, 1999232, 549504, 31616, 128, 256, 128512, 3739648, 22587904, 39984640, 22587904, 3739648, 128512, 256
OFFSET
0,2
FORMULA
T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 2*x + 2.
Sum_{k=0..n} T(n, k) = A002866(n).
From G. C. Greubel, Mar 21 2022: (Start)
T(n, k) = (a*k + b)*T(n-1, k) + (a*(n-k) + b)*T(n-1, k-1), with T(n, 0) = 1, a = 2, and b = 2.
T(n, n-k) = T(n, k).
T(n, 0) = A000079(n).
T(n, 1) = 2*A100575(n+1). (End)
EXAMPLE
Triangle begins as:
1;
2, 2;
4, 16, 4;
8, 88, 88, 8;
16, 416, 1056, 416, 16;
32, 1824, 9664, 9664, 1824, 32;
64, 7680, 76224, 154624, 76224, 7680, 64;
128, 31616, 549504, 1999232, 1999232, 549504, 31616, 128;
256, 128512, 3739648, 22587904, 39984640, 22587904, 3739648, 128512, 256;
MATHEMATICA
T[n_, k_, a_, b_]:= T[n, k, a, b]= If[k<0 || k>n, 0, If[n==0, 1, (a*(n-k)+b)*T[n-1, k-1, a, b] + (a*k+b)*T[n-1, k, a, b]]];
Table[T[n, k, 2, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 21 2022 *)
PROG
(Magma)
function T(n, k, a, b)
if k lt 0 or k gt n then return 0;
elif k eq 0 or k eq n then return 1;
else return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b);
end if; return T;
end function;
[T(n, k, 2, 2): k in [0..n], n in [0..12]]; // G. C. Greubel, Mar 21 2022
(Sage)
def T(n, k, a, b): # A257609
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b)
flatten([[T(n, k, 2, 2) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 21 2022
CROSSREFS
Cf. similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 03 2015
STATUS
approved
Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 3*n + 3.
+10
12
1, 3, 3, 9, 36, 9, 27, 297, 297, 27, 81, 2106, 5346, 2106, 81, 243, 13851, 73386, 73386, 13851, 243, 729, 87480, 868239, 1761264, 868239, 87480, 729, 2187, 540189, 9388791, 34158753, 34158753, 9388791, 540189, 2187, 6561, 3293622, 95843088, 578903274, 1024762590, 578903274, 95843088, 3293622, 6561
OFFSET
0,2
FORMULA
T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 3*n + 3.
Sum_{k=0..n} T(n, k) = A034001(n).
From G. C. Greubel, Feb 28 2022: (Start)
t(k, n) = t(n, k).
T(n, n-k) = T(n, k).
t(0, n) = T(n, 0) = A000244(n). (End)
EXAMPLE
Array t(n,k) begins as:
1, 3, 9, 27, 81, 243, ...;
3, 36, 297, 2106, 13851, 87480, ...;
9, 297, 5346, 73386, 868239, 9388791, ...;
27, 2106, 73386, 1761264, 34158753, 578903274, ...;
81, 13851, 868239, 34158753, 1024762590, 25791697782, ...;
243, 87480, 9388791, 578903274, 25791697782, 928501120152, ...;
729, 540189, 95843088, 8959544136, 575025893586, 28788563928042, ...;
Triangle T(n,k) begins as:
1;
3, 3;
9, 36, 9;
27, 297, 297, 27;
81, 2106, 5346, 2106, 81;
243, 13851, 73386, 73386, 13851, 243;
729, 87480, 868239, 1761264, 868239, 87480, 729;
2187, 540189, 9388791, 34158753, 34158753, 9388791, 540189, 2187;
MATHEMATICA
t[n_, k_, p_, q_]:= t[n, k, p, q] = If[n<0 || k<0, 0, If[n==0 && k==0, 1, (p*k+q)*t[n-1, k, p, q] + (p*n+q)*t[n, k-1, p, q]]];
T[n_, k_, p_, q_]= t[n-k, k, p, q];
Table[T[n, k, 3, 3], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Feb 28 2022 *)
PROG
(Sage)
@CachedFunction
def t(n, k, p, q):
if (n<0 or k<0): return 0
elif (n==0 and k==0): return 1
else: return (p*k+q)*t(n-1, k, p, q) + (p*n+q)*t(n, k-1, p, q)
def A257620(n, k): return t(n-k, k, 3, 3)
flatten([[A257620(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 28 2022
CROSSREFS
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 09 2015
STATUS
approved
Triangle, read by rows, T(n,k) = t(n-k, k) where t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1) and f(n) = 2*n + 3.
+10
11
1, 3, 3, 9, 30, 9, 27, 213, 213, 27, 81, 1308, 2982, 1308, 81, 243, 7431, 32646, 32646, 7431, 243, 729, 40314, 310263, 587628, 310263, 40314, 729, 2187, 212505, 2695923, 8701545, 8701545, 2695923, 212505, 2187, 6561, 1099704, 22059036, 113360904, 191433990, 113360904, 22059036, 1099704, 6561
OFFSET
0,2
FORMULA
T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 2*n + 3.
Sum_{k=0..n} T(n, k) = A051578(n).
From G. C. Greubel, Feb 28 2022: (Start)
t(k, n) = t(n, k).
T(n, n-k) = T(n, k).
t(0, n) = T(n, 0) = A000244(n). (End)
EXAMPLE
Array t(n,k) begins as:
1, 3, 9, 27, 81, 243, ...;
3, 30, 213, 1308, 7431, 40314, ...;
9, 213, 2982, 32646, 310263, 2695923, ...;
27, 1308, 32646, 587628, 8701545, 113360904, ...;
81, 7431, 310263, 8701545, 191433990, 3579465642, ...;
243, 40314, 2695923, 113360904, 3579465642, 93066106692, ...;
729, 212505, 22059036, 1351133676, 59641127202, 2104476295026, ...;
Triangle T(n,k) begins as:
1;
3, 3;
9, 30, 9;
27, 213, 213, 27;
81, 1308, 2982, 1308, 81;
243, 7431, 32646, 32646, 7431, 243;
729, 40314, 310263, 587628, 310263, 40314, 729;
2187, 212505, 2695923, 8701545, 8701545, 2695923, 212505, 2187;
MATHEMATICA
t[n_, k_, p_, q_]:= t[n, k, p, q] = If[n<0 || k<0, 0, If[n==0 && k==0, 1, (p*k+q)*t[n-1, k, p, q] + (p*n+q)*t[n, k-1, p, q]]];
T[n_, k_, p_, q_]= t[n-k, k, p, q];
Table[T[n, k, 2, 3], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Feb 28 2022 *)
PROG
(PARI) f(x) = 2*x + 3;
T(n, k) = t(n-k, k);
t(n, m) = if (!n && !m, 1, if (n < 0 || m < 0, 0, f(m)*t(n-1, m) + f(n)*t(n, m-1)));
tabl(nn) = for (n=0, nn, for (k=0, n, print1(T(n, k), ", "); ); print(); ); \\ Michel Marcus, May 06 2015
(Sage)
@CachedFunction
def t(n, k, p, q):
if (n<0 or k<0): return 0
elif (n==0 and k==0): return 1
else: return (p*k+q)*t(n-1, k, p, q) + (p*n+q)*t(n, k-1, p, q)
def A257611(n, k): return t(n-k, k, 2, 3)
flatten([[A257611(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 28 2022
CROSSREFS
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 06 2015
STATUS
approved
Triangle, read by rows, T(n,k) = t(n-k, k) where t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(x) = x + 3.
+10
10
1, 3, 3, 9, 24, 9, 27, 141, 141, 27, 81, 726, 1410, 726, 81, 243, 3471, 11406, 11406, 3471, 243, 729, 15828, 81327, 136872, 81327, 15828, 729, 2187, 69873, 533259, 1390521, 1390521, 533259, 69873, 2187, 6561, 301362, 3295152, 12609198, 19467294, 12609198, 3295152, 301362, 6561, 19683, 1277619, 19489380, 105311556, 237144642, 237144642, 105311556, 19489380, 1277619, 19683
OFFSET
0,2
FORMULA
T(n,k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(x) = x + 3.
Sum_{k=0..n} T(n, k) = A001725(n+5).
From G. C. Greubel, Feb 22 2022: (Start)
t(k, n) = t(n, k).
T(n, n-k) = T(n, k).
t(0, n) = T(n, 0) = A000244(n). (End)
EXAMPLE
Array t(n,k) begins as:
1, 3, 9, 27, 81, 243, ... A000244;
3, 24, 141, 726, 3471, 15828, ...;
9, 141, 1410, 11406, 81327, 533259, ...;
27, 726, 11406, 136872, 1390521, 12609198, ...;
81, 3471, 81327, 1390521, 19467294, 237144642, ...;
243, 15828, 533259, 12609198, 237144642, 3794314272, ...;
729, 69873, 3295152, 105311556, 2607816498, 53824862658, ...;
Triangle T(n,k) begins as:
1;
3, 3;
9, 24, 9;
27, 141, 141, 27;
81, 726, 1410, 726, 81;
243, 3471, 11406, 11406, 3471, 243;
729, 15828, 81327, 136872, 81327, 15828, 729;
2187, 69873, 533259, 1390521, 1390521, 533259, 69873, 2187;
6561, 301362, 3295152, 12609198, 19467294, 12609198, 3295152, 301362, 6561;
MATHEMATICA
f[n_]:= n+3;
t[n_, k_]:= t[n, k]= If[n<0 || k<0, 0, If[n==0 && k==0, 1, f[k]*t[n-1, k] +f[n]*t[n, k-1]]];
T[n_, k_]= t[n-k, k];
Table[T[n, k], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Feb 22 2022 *)
PROG
(PARI) f(x) = x + 3;
T(n, k) = t(n-k, k);
t(n, m) = {if (!n && !m, return(1)); if (n < 0 || m < 0, return (0)); f(m)*t(n-1, m) + f(n)*t(n, m-1); }
tabl(nn) = {for (n=0, nn, for (k=0, n, print1(T(n, k), ", "); ); print(); ); } \\ Michel Marcus, Apr 23 2015
(Sage)
def f(n): return n+3
@CachedFunction
def t(n, k):
if (n<0 or k<0): return 0
elif (n==0 and k==0): return 1
else: return f(k)*t(n-1, k) + f(n)*t(n, k-1)
def A257627(n, k): return t(n-k, k)
flatten([[A257627(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 22 2022
CROSSREFS
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, Apr 17 2015
STATUS
approved
Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 4*x + 2.
+10
10
1, 2, 2, 4, 24, 4, 8, 184, 184, 8, 16, 1216, 3680, 1216, 16, 32, 7584, 53824, 53824, 7584, 32, 64, 46208, 674752, 1507072, 674752, 46208, 64, 128, 278912, 7764096, 33244544, 33244544, 7764096, 278912, 128, 256, 1677312, 84892672, 636233728, 1196803584, 636233728, 84892672, 1677312, 256
OFFSET
0,2
COMMENTS
Corresponding entries in this triangle and in A060187 differ only by powers of 2. - F. Chapoton, Nov 04 2020
FORMULA
T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 4*x + 2.
Sum_{k=0..n} T(n,k) = A047053(n).
T(n, k) = (a*k + b)*T(n-1, k) + (a*(n-k) + b)*T(n-1, k-1), with T(n, 0) = 1, a = 4, and b = 2. - G. C. Greubel, Mar 20 2022
EXAMPLE
Triangle begins as:
1;
2, 2;
4, 24, 4;
8, 184, 184, 8;
16, 1216, 3680, 1216, 16;
32, 7584, 53824, 53824, 7584, 32;
64, 46208, 674752, 1507072, 674752, 46208, 64;
128, 278912, 7764096, 33244544, 33244544, 7764096, 278912, 128;
MATHEMATICA
T[n_, k_, a_, b_]:= T[n, k, a, b]= If[k<0 || k>n, 0, If[n==0, 1, (a*(n-k)+b)*T[n-1, k-1, a, b] + (a*k+b)*T[n-1, k, a, b]]];
Table[T[n, k, 4, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 20 2022 *)
PROG
(PARI) f(x) = 4*x + 2;
T(n, k) = t(n-k, k);
t(n, m) = if (!n && !m, 1, if (n < 0 || m < 0, 0, f(m)*t(n-1, m) + f(n)*t(n, m-1)));
tabl(nn) = for (n=0, nn, for (k=0, n, print1(T(n, k), ", "); ); print(); ); \\ Michel Marcus, May 06 2015
(Sage)
def T(n, k, a, b): # A257612
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b)
flatten([[T(n, k, 4, 2) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 20 2022
CROSSREFS
Cf. A047053 (row sums), A060187, A142459, A257621.
See similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 06 2015
STATUS
approved
Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 5*n + 2.
+10
10
1, 2, 2, 4, 28, 4, 8, 244, 244, 8, 16, 1844, 5856, 1844, 16, 32, 13260, 101620, 101620, 13260, 32, 64, 93684, 1511160, 3455080, 1511160, 93684, 64, 128, 657836, 20663388, 91981880, 91981880, 20663388, 657836, 128, 256, 4609588, 269011408, 2121603436, 4047202720, 2121603436, 269011408, 4609588, 256
OFFSET
0,2
FORMULA
T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 5*n + 2.
Sum_{k=0..n} T(n, k) = A008546(n).
From G. C. Greubel, Mar 01 2022: (Start)
t(k, n) = t(n, k).
T(n, n-k) = T(n, k).
t(0, n) = T(n, 0) = A000079(n). (End)
EXAMPLE
Array t(n,k) begins as:
1, 2, 4, 8, 16, ... A000079;
2, 28, 244, 1844, 13260, ...;
4, 244, 5856, 101620, 1511160, ...;
8, 1844, 101620, 3455080, 91981880, ...;
16, 13260, 1511160, 91981880, 4047202720, ...;
32, 93684, 20663388, 2121603436, 146321752612, ...;
64, 657836, 269011408, 44675623468, 4648698508440, ...;
Triangle T(n,k) begins as:
1;
2, 2;
4, 28, 4;
8, 244, 244, 8;
16, 1844, 5856, 1844, 16;
32, 13260, 101620, 101620, 13260, 32;
64, 93684, 1511160, 3455080, 1511160, 93684, 64;
128, 657836, 20663388, 91981880, 91981880, 20663388, 657836, 128;
MATHEMATICA
t[n_, k_, p_, q_]:= t[n, k, p, q] = If[n<0 || k<0, 0, If[n==0 && k==0, 1, (p*k+q)*t[n-1, k, p, q] + (p*n+q)*t[n, k-1, p, q]]];
T[n_, k_, p_, q_]= t[n-k, k, p, q];
Table[T[n, k, 5, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 01 2022 *)
PROG
(Sage)
@CachedFunction
def t(n, k, p, q):
if (n<0 or k<0): return 0
elif (n==0 and k==0): return 1
else: return (p*k+q)*t(n-1, k, p, q) + (p*n+q)*t(n, k-1, p, q)
def A257614(n, k): return t(n-k, k, 5, 2)
flatten([[A257614(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 01 2022
CROSSREFS
Cf. A000079, A008546 (row sums), A142460, A257623.
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 09 2015
STATUS
approved
Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 6*x + 2.
+10
10
1, 2, 2, 4, 32, 4, 8, 312, 312, 8, 16, 2656, 8736, 2656, 16, 32, 21664, 175424, 175424, 21664, 32, 64, 174336, 3019200, 7016960, 3019200, 174336, 64, 128, 1397120, 47847552, 218838400, 218838400, 47847552, 1397120, 128, 256, 11182592, 722956288, 5907889664, 11379596800, 5907889664, 722956288, 11182592, 256
OFFSET
0,2
FORMULA
T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 6*x + 2.
Sum_{k=0..n} T(n, k) = A049308(n).
From G. C. Greubel, Mar 21 2022: (Start)
T(n, k) = (a*k + b)*T(n-1, k) + (a*(n-k) + b)*T(n-1, k-1), with T(n, 0) = 1, a = 6, and b = 2.
T(n, n-k) = T(n, k).
T(n, 0) = A000079(n).
T(n, 1) = (2^n/3)*(2^(2*n+1) - (3*n+2)). (End)
EXAMPLE
Triangle begins as:
1;
2, 2;
4, 32, 4;
8, 312, 312, 8;
16, 2656, 8736, 2656, 16;
32, 21664, 175424, 175424, 21664, 32;
64, 174336, 3019200, 7016960, 3019200, 174336, 64;
128, 1397120, 47847552, 218838400, 218838400, 47847552, 1397120, 128;
MATHEMATICA
T[n_, k_, a_, b_]:= T[n, k, a, b]= If[k<0 || k>n, 0, If[n==0, 1, (a*(n-k)+b)*T[n-1, k-1, a, b] + (a*k+b)*T[n-1, k, a, b]]];
Table[T[n, k, 6, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 21 2022 *)
PROG
(Sage)
def T(n, k, a, b): # A257610
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b)
flatten([[T(n, k, 6, 2) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 21 2022
CROSSREFS
Cf. A000079, A049308 (row sums), A142461, A257625.
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 09 2015
STATUS
approved
Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 7*x + 2.
+10
10
1, 2, 2, 4, 36, 4, 8, 388, 388, 8, 16, 3676, 12416, 3676, 16, 32, 33564, 283204, 283204, 33564, 32, 64, 303260, 5538184, 13027384, 5538184, 303260, 64, 128, 2732156, 99831564, 465775352, 465775352, 99831564, 2732156, 128
OFFSET
0,2
FORMULA
T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 7*x + 2.
Sum_{k=0..n} T(n, k) = A144827(n).
From G. C. Greubel, Mar 24 2022: (Start)
T(n, k) = (a*k + b)*T(n-1, k) + (a*(n-k) + b)*T(n-1, k-1), with T(n, 0) = 1, a = 7, and b = 2.
T(n, n-k) = T(n, k).
T(n, 0) = A000079(n).
T(n, 1) = (4*9^n - 2^n*(7*n + 4))/7.
T(n, 2) = (2^(n-1)*(49*n^2 +7*n -12) + 11*2^(4*n+1) - 4*(7*n+4)*9^n)/49. (End)
EXAMPLE
1;
2, 2;
4, 36, 4;
8, 388, 388, 8;
16, 3676, 12416, 3676, 16;
32, 33564, 283204, 283204, 33564, 32;
64, 303260, 5538184, 13027384, 5538184, 303260, 64;
128, 2732156, 99831564, 465775352, 465775352, 99831564, 2732156, 128;
MATHEMATICA
T[n_, k_, a_, b_]:= T[n, k, a, b]= If[k<0 || k>n, 0, If[n==0, 1, (a*(n-k)+b)*T[n-1, k-1, a, b] + (a*k+b)*T[n-1, k, a, b]]];
Table[T[n, k, 7, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 24 2022 *)
PROG
(Sage)
def T(n, k, a, b): # A257617
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b)
flatten([[T(n, k, 7, 2) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 24 2022
CROSSREFS
Cf. A000079, A142462, A144827 (row sums), A257627.
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 09 2015
STATUS
approved
Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 9*x + 2.
+10
10
1, 2, 2, 4, 44, 4, 8, 564, 564, 8, 16, 6436, 22560, 6436, 16, 32, 71404, 637844, 637844, 71404, 32, 64, 786948, 15470232, 36994952, 15470232, 786948, 64, 128, 8660012, 346391196, 1660722424, 1660722424, 346391196, 8660012, 128
OFFSET
0,2
FORMULA
T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 9*x + 2.
Sum_{k=0..n} T(n, k) = A144829(n).
From G. C. Greubel, Mar 24 2022: (Start)
T(n, k) = (a*k + b)*T(n-1, k) + (a*(n-k) + b)*T(n-1, k-1), with T(n, 0) = 1, a = 9, and b = 2.
T(n, n-k) = T(n, k).
T(n, 0) = A000079(n).
T(n, 1) = (1/9)*(4*11^n - 2^n*(9*n + 4)).
T(n, 2) = (1/81)*(26*20^n - 4*(4+9*n)*11^n - 2^(n-1)*(20 + 9*n - 81*n^2)). (End)
EXAMPLE
Triangle begins as:
1;
2, 2;
4, 44, 4;
8, 564, 564, 8;
16, 6436, 22560, 6436, 16;
32, 71404, 637844, 637844, 71404, 32;
64, 786948, 15470232, 36994952, 15470232, 786948, 64;
128, 8660012, 346391196, 1660722424, 1660722424, 346391196, 8660012, 128;
MATHEMATICA
T[n_, k_, a_, b_]:= T[n, k, a, b]= If[k<0 || k>n, 0, If[n==0, 1, (a*(n-k)+b)*T[n-1, k-1, a, b] + (a*k+b)*T[n-1, k, a, b]]];
Table[T[n, k, 9, 2], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 24 2022 *)
PROG
(PARI) f(x) = 9*x + 2;
t(n, m) = if ((n<0) || (m<0), 0, if ((n==0) && (m==0), 1, f(m)*t(n-1, m) + f(n)*t(n, m-1)));
tabl(nn) = {for (n=0, nn, for (k=0, n, print1(t(n-k, k), ", "); ); print(); ); } \\ Michel Marcus, May 23 2015
(Sage)
def T(n, k, a, b): # A257619
if (k<0 or k>n): return 0
elif (n==0): return 1
else: return (a*k+b)*T(n-1, k, a, b) + (a*(n-k)+b)*T(n-1, k-1, a, b)
flatten([[T(n, k, 9, 2) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 24 2022
CROSSREFS
Cf. A000079, A144829 (row sums), A257608.
Similar sequences listed in A256890.
KEYWORD
nonn,tabl
AUTHOR
Dale Gerdemann, May 09 2015
STATUS
approved

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