OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..40
S. B. Ekhad, D. Zeilberger, Computational and Theoretical Challenges on Counting Solid Standard Young Tableaux, arXiv:1202.6229v1 [math.CO], 2012
Wikipedia, Young tableau
MAPLE
b:= proc(w, x, y, z, u) option remember;
`if`({w, x, y, z, u}={0}, 1, `if`(w>x and w>u, b(w-1, x, y, z, u), 0)+
`if`(x>y, b(w, x-1, y, z, u), 0)+ `if`(y>z, b(w, x, y-1, z, u), 0)+
`if`(z>0, b(w, x, y, z-1, u), 0)+ `if`(u>0, b(w, x, y, z, u-1), 0))
end:
a:= n-> b(n$5):
seq(a(n), n=0..20);
MATHEMATICA
b[w_, x_, y_, z_, u_] := b[w, x, y, z, u] =
If[Union@{w, x, y, z, u} == {0}, 1,
If[w > x && w > u, b[w - 1, x, y, z, u], 0] +
If[x > y, b[w, x - 1, y, z, u], 0] +
If[y > z, b[w, x, y - 1, z, u], 0] +
If[z > 0, b[w, x, y, z - 1, u], 0] +
If[u > 0, b[w, x, y, z, u - 1], 0]];
a[n_] := b[n, n, n, n, n];
Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Nov 08 2017, translated from Maple *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Aug 06 2012
STATUS
approved