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A182114
Number of partitions of n with largest inscribed rectangle having area <= k; triangle T(n,k), 0<=n, 0<=k<=n, read by rows.
13
1, 0, 1, 0, 0, 2, 0, 0, 1, 3, 0, 0, 0, 2, 5, 0, 0, 0, 1, 5, 7, 0, 0, 0, 0, 5, 7, 11, 0, 0, 0, 0, 3, 7, 13, 15, 0, 0, 0, 0, 1, 5, 16, 18, 22, 0, 0, 0, 0, 0, 3, 17, 21, 27, 30, 0, 0, 0, 0, 0, 1, 16, 22, 34, 38, 42, 0, 0, 0, 0, 0, 0, 13, 21, 39, 48, 54, 56
OFFSET
0,6
COMMENTS
T(n,k) = A000041(k) for n<k is omitted from the triangle.
Sum_{n>=0} T(n,k) = A115725(k).
LINKS
FORMULA
T(n,k) = Sum_{i=1..k} A115723(n,i) for n>0, T(0,0) = 1.
EXAMPLE
T(5,4) = 5 because there are 5 partitions of 5 with largest inscribed rectangle having area <= 4: [1,1,1,2], [1,2,2], [1,1,3], [2,3], [1,4].
T(9,5) = 3: [1,1,1,2,4], [1,1,1,1,5], [1,1,2,5].
Triangle T(n,k) begins:
1;
0, 1;
0, 0, 2;
0, 0, 1, 3;
0, 0, 0, 2, 5;
0, 0, 0, 1, 5, 7;
0, 0, 0, 0, 5, 7, 11;
0, 0, 0, 0, 3, 7, 13, 15;
0, 0, 0, 0, 1, 5, 16, 18, 22;
0, 0, 0, 0, 0, 3, 17, 21, 27, 30;
0, 0, 0, 0, 0, 1, 16, 22, 34, 38, 42;
...
MAPLE
b:= proc(n, i, t, k) option remember; `if`(n=0, 1,
`if`(i=1, `if`(t+n<=k, 1, 0), `if`(i<1, 0, b(n, i-1, t, k)+
add(`if`(t+j<=k/i, b(n-i*j, i-1, t+j, k), 0), j=1..n/i))))
end:
T:= (n, k)-> b(n, n, 0, k):
seq(seq(T(n, k), k=0..n), n=0..15);
MATHEMATICA
b[n_, i_, t_, k_] := b[n, i, t, k] = If[n == 0, 1, If[i == 1, If[t + n <= k, 1, 0], If[i < 1, 0, b[n, i - 1, t, k] + Sum[If[t + j <= k/i, b[n - i*j, i - 1, t + j, k], 0], {j, 1, n/i}]]]] ; T[n_, k_] := b[n, n, 0, k]; Table[Table[T[n, k], {k, 0, n}], {n, 0, 15}] // Flatten (* Jean-François Alcover, Dec 27 2013, translated from Maple *)
CROSSREFS
Diagonal gives: A000041.
T(n,n-1) = A144300(n) = A000041(n) - A000005(n).
T(n+d,n) for d=2-10 give: A218623, A218624, A218625, A218626, A218627, A218628, A218629, A218630, A218631.
Sequence in context: A258651 A350530 A258850 * A122950 A374766 A116489
KEYWORD
nonn,look,tabl
AUTHOR
Alois P. Heinz, Apr 12 2012
STATUS
approved