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.

A176129 Number A(n,k) of solid standard Young tableaux of shape [[n*k,n],[n]]; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

1, 1, 0, 1, 2, 0, 1, 6, 16, 0, 1, 12, 174, 192, 0, 1, 20, 690, 7020, 2816, 0, 1, 30, 1876, 52808, 325590, 46592, 0, 1, 42, 4140, 229680, 4558410, 16290708, 835584, 0, 1, 56, 7986, 738192, 31497284, 420421056, 854630476, 15876096, 0
Offset: 0

Views

Author

Alois P. Heinz, Jul 29 2012

Keywords

Comments

In general, column k is (for k > 1) asymptotic to sqrt((k+2)*(k^2 - 20*k - 8 + sqrt(k*(k+8)^3)) / (8*k^3)) * ((k+2)^(k+2)/k^k)^n / (Pi*n). - Vaclav Kotesovec, Aug 31 2014

Examples

			Square array A(n,k) begins:
  1,      1,        1,         1,          1,           1, ...
  0,      2,        6,        12,         20,          30, ...
  0,     16,      174,       690,       1876,        4140, ...
  0,    192,     7020,     52808,     229680,      738192, ...
  0,   2816,   325590,   4558410,   31497284,   146955276, ...
  0,  46592, 16290708, 420421056, 4600393936, 31113230148, ...
		

Crossrefs

Rows n=0-3 give: A000012, A002378, A215687, A215688.
Main diagonal gives: A215123.

Programs

  • Maple
    b:= proc(x, y, z) option remember; `if`(z>y, b(x, z, y), `if`(z>x, 0,
          `if`({x, y, z}={0}, 1, `if`(x>y and x>z, b(x-1, y, z), 0)+
          `if`(y>0, b(x, y-1, z), 0)+ `if`(z>0, b(x, y, z-1), 0))))
        end:
    A:= (n, k)-> b(n*k, n, n):
    seq(seq(A(n, d-n), n=0..d), d=0..8);
  • Mathematica
    b [x_, y_, z_] := b[x, y, z] = If[z > y, b[x, z, y], If[z > x, 0, If[Union[{x, y, z}] == {0}, 1, If[x > y && x > z, b[x-1, y, z], 0] + If[y > 0, b[x, y-1, z], 0] + If[z > 0, b[x, y, z-1], 0]]]]; a[n_, k_] := b[n*k, n, n]; Table[Table[a[n, d-n], {n, 0, d}], {d, 0, 8}] // Flatten (* Jean-François Alcover, Dec 11 2013, translated from Maple *)