OFFSET
0,6
LINKS
Alois P. Heinz, Antidiagonals n = 0..50
Wikipedia, Young tableau
EXAMPLE
A(3,2) = 1^2 + 2^2 + 1^2 = 6 = 3! because 3 has partitions 111, 21, 3 with 1, 2, 1 standard Young tableaux, respectively:
.111. . 21 . . . . . . . . 3 . . . .
+---+ +------+ +------+ +---------+
| 1 | | 1 2 | | 1 3 | | 1 2 3 |
| 2 | | 3 .--+ | 2 .--+ +---------+
| 3 | +---+ +---+
+---+
Square array A(n,k) begins:
1, 1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, 1, ...
2, 2, 2, 2, 2, 2, 2, ...
3, 4, 6, 10, 18, 34, 66, ...
5, 10, 24, 64, 180, 520, 1524, ...
7, 26, 120, 596, 3060, 16076, 86100, ...
11, 76, 720, 8056, 101160, 1379176, 19902600, ...
MAPLE
h:= proc(l) local n; n:=nops(l); add(i, i=l)! /mul(mul(1+l[i]-j
+add(`if`(l[k]>=j, 1, 0), k=i+1..n), j=1..l[i]), i=1..n)
end:
g:= proc(n, i, k, l) `if`(n=0, h(l)^k, `if`(i<1, 0, g(n, i-1, k, l)
+ `if`(i>n, 0, g(n-i, i, k, [l[], i]))))
end:
A:= (n, k)-> `if`(n=0, 1, g(n, n, k, [])):
seq(seq(A(n, d-n), n=0..d), d=0..10);
MATHEMATICA
h[l_] := With[{n = Length[l]}, Sum[i, {i, l}]! / Product[Product[1 + l[[i]] - j + Sum [If[l[[k]] >= j, 1, 0], { k, i+1, n}], {j, 1, l[[i]]}], {i, 1, n}]]; g[n_, i_, k_, l_] := If[n == 0, h[l]^k, If[i < 1, 0, g[n, i-1, k, l] + If[i > n, 0, g[n-i, i, k, Append[l, i]]]]]; a [n_, k_] := If[n == 0, 1, g[n, n, k, {}]]; Table[Table[a[n, d-n], {n, 0, d}], {d, 0, 10}] // Flatten (* Jean-François Alcover, Dec 11 2013, translated from Maple *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Feb 26 2012
STATUS
approved