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

8,1

Links

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

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);

Crossrefs

Column k=8 of A291680.

Sequence in context: A253733 A241102 A292545 * A253732 A232513 A224741

Adjacent sequences: A321112 A321113 A321114 * A321116 A321117 A321118

Keyword

nonn

Author

Alois P. Heinz, Oct 27 2018

Status

approved