A241785 Number of standard Young tableaux with 2n cells and exactly n successions.

1, 1, 2, 9, 49, 322, 2411, 19868, 178832, 1724689, 17728545, 192634930, 2201760840, 26341552085, 328644606302, 4261866683006, 57288746422850, 796337785825197, 11422744246417607, 168765251734898485, 2564015637845130072, 39998356172536082076, 639840751503820832346

Offset: 0

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

• nonn

Comments

A succession is a pair of cells (v, v+1) lying in the same row.

Also number of ballot sequences of length 2n having exactly n flat steps.

Formula

a(n) = A238125(2n,n).