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.

A208447 Sum of the k-th powers of the numbers of standard Young tableaux over all partitions of n; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 4, 5, 1, 1, 2, 6, 10, 7, 1, 1, 2, 10, 24, 26, 11, 1, 1, 2, 18, 64, 120, 76, 15, 1, 1, 2, 34, 180, 596, 720, 232, 22, 1, 1, 2, 66, 520, 3060, 8056, 5040, 764, 30, 1, 1, 2, 130, 1524, 16076, 101160, 130432, 40320, 2620, 42
Offset: 0

Views

Author

Alois P. Heinz, Feb 26 2012

Keywords

Examples

			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, ...
		

Crossrefs

Rows 0+1, 2, 3 give: A000012, A007395, A052548.
Main diagonal gives A319607.

Programs

  • 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 *)