A238127 Number of standard Young tableaux with n cells and exactly two successions.

0, 0, 0, 1, 2, 6, 17, 57, 191, 663, 2415, 9108, 35695, 143989, 599802, 2566917, 11298164, 50967216, 235745644, 1115324000, 5397332497, 26669487517, 134528555379, 691856601631, 3626390958551, 19353306241764, 105122093620388, 580689432523534, 3260906342453966

Offset: 0

Author

Joerg Arndt and Alois P. Heinz, Feb 21 2014

Keywords

• nonn

Comments

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

Also number of ballot sequences having two flat steps.

Third column (k=2) of A238125.

Crossrefs

Cf. A237770 (no successions), A238126 (one succession).