cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A215086 Number A(n,k) of solid standard Young tableaux of n cells and height <= k; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 1, 2, 0, 1, 1, 3, 4, 0, 1, 1, 3, 8, 10, 0, 1, 1, 3, 9, 26, 26, 0, 1, 1, 3, 9, 32, 92, 76, 0, 1, 1, 3, 9, 33, 126, 372, 232, 0, 1, 1, 3, 9, 33, 134, 564, 1566, 764, 0, 1, 1, 3, 9, 33, 135, 622, 2700, 7086, 2620, 0, 1, 1, 3, 9, 33, 135, 632, 3106, 13802, 33550, 9496, 0
Offset: 0

Views

Author

Alois P. Heinz, Aug 02 2012

Keywords

Examples

			Square array A(n,k) begins:
  1,   1,    1,    1,    1,    1,    1,    1, ...
  0,   1,    1,    1,    1,    1,    1,    1, ...
  0,   2,    3,    3,    3,    3,    3,    3, ...
  0,   4,    8,    9,    9,    9,    9,    9, ...
  0,  10,   26,   32,   33,   33,   33,   33, ...
  0,  26,   92,  126,  134,  135,  135,  135, ...
  0,  76,  372,  564,  622,  632,  633,  633, ...
  0, 232, 1566, 2700, 3106, 3194, 3206, 3207, ...
		

Crossrefs

Rows n=0-1 give: A000012, A057427.
Main diagonal gives A207542.
Cf. A214753.

Programs

  • Maple
    b:= proc(n, k, l) option remember; `if`(n=0, 1,
           b(n-1, k, [l[], [1]])+ add(`if`(i=1 or nops(l[i]) `if`(k=0, `if`(n=0, 1, 0), b(n, min(n, k), [])):
    seq(seq(A(n, d-n), n=0..d), d=0..10);
  • Mathematica
    b[n_, k_, l_] := b[n, k, l] = If[n==0, 1, b[n-1, k, Append[l, {1}]] + Sum[If[i==1 || Length[l[[i]]] Append[l[[i]], 1]]], 0] + Sum[If[l[[i, j]] ReplacePart[ l[[i]], j -> l[[i, j]]+1]]], 0], {j, 1, Length[l[[i]]]} ], {i, 1, Length[l]}]]; A[n_, k_] := If[k==0, If[n==0, 1, 0], b[n, Min[n, k], {}]]; Table[A[n, d-n], {d, 0, 11}, {n, 0, d}] // Flatten (* Jean-François Alcover, Jan 26 2017, after Alois P. Heinz *)

Formula

A(n,k) = Sum_{i=0..k} A214753(n,i).