A321115 Number of permutations p of [n] such that in 0p the largest up-jump equals eight and no down-jump is larger than 2.

218, 1672, 11840, 80724, 540122, 3577200, 23538730, 154134422, 1004867492, 6532643538, 42400841816, 274916251180, 1781266093356, 11536471789526, 74699007947826, 483632170943926, 3131266103627660, 20275073235017968, 131300482646184366, 850449366760216588

Offset: 8

Author

Alois P. Heinz, Oct 27 2018

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 8..1000

Crossrefs

Column k=8 of A291680.

Programs

Maple

b:= proc(u, o, k) option remember; `if`(u+o=0, 1,
      add(b(u-j, o+j-1, k), j=1..min(2, u))+
      add(b(u+j-1, o-j, k), j=1..min(k, o)))
    end:
a:= n-> (k-> b(0, n, k)-b(0, n, k-1))(8):
seq(a(n), n=8..30);