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.

A264103 Number of n X n nonconsecutive tableaux.

Original entry on oeis.org

1, 1, 1, 6, 1289, 13652068, 11865331748843, 1232033659827201777222, 20955050449849509663209289613921, 76615072242390448445916336191834325715261848, 76456972050113830615729276134092575545874371011199394401950, 25770844284993968943713846068617488831241440984966512955013952234546614462044
Offset: 0

Views

Author

Alois P. Heinz, Nov 03 2015

Keywords

Comments

A standard Young tableau (SYT) where entries i and i+1 never appear in the same row is called a nonconsecutive tableau.

Examples

			a(3) = 6:
  [1 4 7]  [1 3 7]  [1 4 6]  [1 3 6]  [1 3 6]  [1 3 5]
  [2 5 8]  [2 5 8]  [2 5 8]  [2 5 8]  [2 4 8]  [2 6 8]
  [3 6 9]  [4 6 9]  [3 7 9]  [4 7 9]  [5 7 9]  [4 7 9].
		

Crossrefs

Main diagonal of A214021.

Programs

  • Mathematica
    b[l_, t_] := b[l, t] = Module[{n = Length[l], s = Total[l]}, If[s == 0, 1, Sum[If[t != i && l[[i]] > If[i == n, 0, l[[i+1]]], b[ReplacePart[l, i -> l[[i]]-1], i], 0], {i, 1, n}]]];
    a[n_] := a[n] = If[n<1, 1, b[Array[n&, n], 0]];
    Table[Print[n, " ", a[n]]; a[n], {n, 0, 11}] (* Jean-François Alcover, Sep 08 2021, after Alois P. Heinz in A214021 *)

Formula

a(n) = A214021(n,n).