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Search: a025443 -id:a025443
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Number T(n,k) of partitions of n into k distinct nonzero squares; triangle T(n,k), n>=0, 0<=k<=A248509(n), read by rows.
+10
20
1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1
OFFSET
0
COMMENTS
T(n,k) is defined for n, k >= 0. The triangle contains only the terms with 0 <= k <= A248509(n). T(n,k) = 0 for k > A248509(n).
LINKS
FORMULA
T(n,k) = [x^n*y^k] Product_{j>=1} (1 + y*x^(j^2)).
T(A000330(n),n) = 1.
Row n = [0] <=> n in { A001422 }.
Sum_{k>=0} 2^k * T(n,k) = A279360(n).
Sum_{k>=0} k * T(n,k) = A281542(n).
Sum_{k>=0} (-1)^k * T(n,k) = A276516(n).
EXAMPLE
T(62,3) = 2 is the first term > 1 and counts partitions [49,9,4] and [36,25,1].
Triangle T(n,k) begins:
1;
0, 1;
0;
0;
0, 1;
0, 0, 1;
0;
0;
0;
0, 1;
0, 0, 1;
0;
0;
0, 0, 1;
0, 0, 0, 1;
...
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
b(n, i-1)+`if`(i^2>n, 0, expand(b(n-i^2, i-1)*x))))
end:
T:= n->(p->seq(coeff(p, x, i), i=0..max(0, degree(p))))(b(n, isqrt(n))):
seq(T(n), n=0..45);
MATHEMATICA
b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 1, 0,
b[n, i - 1] + If[i^2 > n, 0, Expand[b[n - i^2, i - 1]*x]]]];
T[n_] := CoefficientList[b[n, Floor@Sqrt[n]], x] /. {} -> {0};
T /@ Range[0, 45] // Flatten (* Jean-François Alcover, Feb 15 2021, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn,look,tabf
AUTHOR
Alois P. Heinz, Feb 03 2021
STATUS
approved
Numbers that are the sum of 4 distinct nonzero squares: of form w^2+x^2+y^2+z^2 with 0<w<x<y<z.
+10
17
30, 39, 46, 50, 51, 54, 57, 62, 63, 65, 66, 70, 71, 74, 75, 78, 79, 81, 84, 85, 86, 87, 90, 91, 93, 94, 95, 98, 99, 102, 105, 106, 107, 109, 110, 111, 113, 114, 116, 117, 118, 119, 120, 121, 122, 123, 125, 126, 127, 129, 130, 131, 133, 134, 135, 137
OFFSET
1,1
FORMULA
{n: A025443(n) >=1}. Union of A025386 and A025376. - R. J. Mathar, Jun 15 2018
EXAMPLE
30 = 1^2+2^2+3^2+4^2.
MATHEMATICA
data = Flatten[ DeleteCases[ FindInstance[ w^2 + x^2 + y^2 + z^2 == # && 0 < w < x < y < z < #, {w, x, y, z}, Integers] & /@ Range[137], {}], 1]; w^2 + x^2 + y^2 + z^2 /. data (* Ant King, Oct 17 2010 *)
Select[Union[Total[#^2]&/@Subsets[Range[10], {4}]], #<=137&] (* Harvey P. Dale, Jul 03 2011 *)
PROG
(Haskell)
a004433 n = a004433_list !! (n-1)
a004433_list = filter (p 4 $ tail a000290_list) [1..] where
p k (q:qs) m = k == 0 && m == 0 ||
q <= m && k >= 0 && (p (k - 1) qs (m - q) || p k qs m)
-- Reinhard Zumkeller, Apr 22 2013
(PARI) list(lim)=my(v=List()); lim\=1; for(z=4, sqrtint(lim\4), for(y=3, min(sqrtint((lim-z^2)\3), z-1), for(x=2, min(sqrtint((lim-y^2-z^2)\2), y-1), for(w=1, min(sqrtint(lim-x^2-y^2-z^2), x-1), listput(v, w^2+x^2+y^2+z^2))))); Set(v) \\ Charles R Greathouse IV, Feb 07 2017
KEYWORD
nonn,easy,nice
STATUS
approved
Least sum of 4 distinct nonzero squares in exactly n ways.
+10
10
30, 90, 78, 142, 126, 174, 190, 210, 286, 351, 294, 318, 270, 330, 430, 390, 414, 550, 450, 582, 594, 546, 462, 606, 510, 862, 786, 726, 770, 714, 690, 630, 702, 846, 810, 750, 1074, 798, 930, 870, 1026, 966, 1246, 1150, 1310, 1190, 1122, 1314, 1338, 1365, 1050
OFFSET
1,1
FORMULA
{min k: A025443(k) = n}. - R. J. Mathar, Jun 15 2018
KEYWORD
nonn
STATUS
approved
a(n) is the smallest number which can be represented as the sum of n distinct nonzero n-gonal numbers in exactly n ways, or 0 if no such number exists.
+10
9
37, 142, 285, 536, 911, 1268, 1909, 2713, 3876, 5179, 6891, 8901, 11190, 14384, 18087, 21697, 27055, 32166, 39111, 46560, 53892, 64412, 73949, 86778, 98202, 113635, 130088, 148051, 167505, 190968, 214955, 240143, 269775, 297615, 331201, 367429, 409179, 451340, 497830
OFFSET
3,1
LINKS
Eric Weisstein's World of Mathematics, Polygonal Number
FORMULA
a(n) >= A006484(n). - David A. Corneth, Dec 30 2021
EXAMPLE
For n = 3: 37 = 1 + 15 + 21 = 3 + 6 + 28 = 6 + 10 + 21.
MATHEMATICA
Do[i=1; While[b=PolygonalNumber[n, Range@i++]; !IntegerQ[t=Min[First/@Select[Tally[Select[Total/@Subsets[b, {n}], #<=Max@b&]], Last@#==n&]]]]; Print@t, {n, 3, 10}] (* Giorgos Kalogeropoulos, Dec 30 2021 *)
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 29 2021
EXTENSIONS
a(10)-a(31) from Michael S. Branicky, Dec 29 2021
More terms from David A. Corneth, Dec 30 2021
STATUS
approved
Number of partitions of n into 5 distinct nonzero squares.
+10
8
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 2, 0, 0, 1, 0
OFFSET
0,104
FORMULA
a(n) = [x^n y^5] Product_{k>=1} (1 + y*x^(k^2)). - Ilya Gutkovskiy, Apr 22 2019
EXAMPLE
a(111) = 2 via 1 + 4 + 9 + 16 + 81 = 1 + 9 + 16 + 36 + 49. - David A. Corneth, Feb 02 2021
MAPLE
From R. J. Mathar, Oct 18 2010: (Start)
A025444aux := proc(n, m, nmax) local a, m, upn, lv ; if m = 1 then if issqr(n) and nmax^2 >= n and n >= 1 then return 1; else return 0; end if; else a := 0 ; for upn from 1 to nmax do lv := n-upn^2 ; if lv <0 then break; end if; a := a + procname(lv, m-1, upn-1) ; end do: return a; end if; end proc:
A025444 := proc(n) A025444aux(n, 5, n) ; end proc: (End)
KEYWORD
nonn,look
STATUS
approved
Number of partitions of n into 9 distinct nonzero squares.
+10
7
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 2, 0, 0, 0, 1, 2, 0, 0, 2
OFFSET
285,92
EXAMPLE
a(381) = 2 via 1 + 4 + 9 + 16 + 36 + 49 + 64 + 81 + 121 = 1 + 9 + 16 + 25 + 36 + 49 + 64 + 81 + 100. - David A. Corneth, Feb 02 2021
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 02 2021
STATUS
approved
Number of partitions of n into 10 distinct nonzero squares.
+10
7
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 1
OFFSET
385,97
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 02 2021
STATUS
approved
Number of partitions of n into 6 distinct nonzero squares.
+10
6
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 2, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 3, 2, 0, 1, 2, 1, 1, 1, 0, 3, 0, 0, 4, 1, 0, 1
OFFSET
91,46
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 02 2021
STATUS
approved
Number of partitions of n into 7 distinct nonzero squares.
+10
6
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 2, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 2, 0, 0, 1, 0, 1, 0, 1, 2, 0, 0, 0, 2, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 2, 3, 0, 0, 2, 2
OFFSET
140,61
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 02 2021
STATUS
approved
Number of partitions of n into 8 distinct nonzero squares.
+10
6
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 2, 0, 0, 1, 0, 1, 0, 0, 2, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 3, 0, 0, 1
OFFSET
204,73
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 02 2021
STATUS
approved

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