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A264910 Number of 5-ascent sequences of length n with no consecutive repeated letters. 2

%I

%S 1,1,5,30,195,1380,10555,86815,764350,7174420,71532369,755136887,

%T 8415519048,98744576456,1216948265335,15718032335081,212330461568282,

%U 2994374695258034,44008250794756373,672986694107199687,10692604102273015636,176266660430175342285

%N Number of 5-ascent sequences of length n with no consecutive repeated letters.

%H Alois P. Heinz, <a href="/A264910/b264910.txt">Table of n, a(n) for n = 0..200</a>

%H S. Kitaev, J. Remmel, <a href="https://arxiv.org/abs/1503.00914">p-Ascent Sequences</a>, arXiv:1503.00914 [math.CO], 2015

%p b:= proc(n, i, t) option remember; `if`(n<1, 1, add(

%p `if`(j=i, 0, b(n-1, j, t+`if`(j>i, 1, 0))), j=0..t+5))

%p end:

%p a:= n-> (b(n-1, 0$2)):

%p seq(a(n), n=0..30);

%t b[n_, i_, t_] := b[n, i, t] = If[n<1, 1, Sum[If[j==i, 0, b[n-1, j, t + If[j>i, 1, 0]]], {j, 0, t+5}]];

%t a[n_] := b[n-1, 0, 0];

%t Table[a[n], {n, 0, 30}] (* _Jean-François Alcover_, Aug 14 2017, translated from Maple *)

%Y Column k=5 of A264909.

%K nonn

%O 0,3

%A _Alois P. Heinz_, Nov 28 2015

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Last modified July 10 12:34 EDT 2020. Contains 335576 sequences. (Running on oeis4.)