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

0,3

Links

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

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);

Crossrefs

Column k=7 of A264909.

Sequence in context: A147839 A126694 A305198 * A323216 A024091 A145302

Adjacent sequences: A264909 A264910 A264911 * A264913 A264914 A264915

Keyword

nonn

Author

Alois P. Heinz, Nov 28 2015

Status

approved