cp's OEIS Frontend

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

%I A264912 #4 Nov 28 2015 18:36:13
%S A264912 1,1,7,56,476,4312,41468,422128,4536140,51328018,610168496,7604171722,
%T A264912 99154078394,1350325442746,19173655721912,283420080801700,
%U A264912 4354942891383206,69465537443190352,1148784383085885884,19673049517219904032,348483690687062619926
%N A264912 Number of 7-ascent sequences of length n with no consecutive repeated letters.
%H A264912 Alois P. Heinz, <a href="/A264912/b264912.txt">Table of n, a(n) for n = 0..200</a>
%p A264912 b:= proc(n, i, t) option remember; `if`(n<1, 1, add(
%p A264912       `if`(j=i, 0, b(n-1, j, t+`if`(j>i, 1, 0))), j=0..t+7))
%p A264912     end:
%p A264912 a:= n-> (b(n-1, 0$2)):
%p A264912 seq(a(n), n=0..30);
%Y A264912 Column k=7 of A264909.
%K A264912 nonn
%O A264912 0,3
%A A264912 _Alois P. Heinz_, Nov 28 2015