A264912 Number of 7-ascent sequences of length n with no consecutive repeated letters.

1, 1, 7, 56, 476, 4312, 41468, 422128, 4536140, 51328018, 610168496, 7604171722, 99154078394, 1350325442746, 19173655721912, 283420080801700, 4354942891383206, 69465537443190352, 1148784383085885884, 19673049517219904032, 348483690687062619926

Offset: 0

Author

Alois P. Heinz, Nov 28 2015

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..200

Crossrefs

Column k=7 of A264909.

Programs

Maple

b:= proc(n, i, t) option remember; `if`(n<1, 1, add(
      `if`(j=i, 0, b(n-1, j, t+`if`(j>i, 1, 0))), j=0..t+7))
    end:
a:= n-> (b(n-1, 0$2)):
seq(a(n), n=0..30);