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

1, 1, 5, 30, 195, 1380, 10555, 86815, 764350, 7174420, 71532369, 755136887, 8415519048, 98744576456, 1216948265335, 15718032335081, 212330461568282, 2994374695258034, 44008250794756373, 672986694107199687, 10692604102273015636, 176266660430175342285

Offset

0,3

Links

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

S. Kitaev, J. Remmel, p-Ascent Sequences, arXiv:1503.00914 [math.CO], 2015

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+5))
    end:
a:= n-> (b(n-1, 0$2)):
seq(a(n), n=0..30);

Mathematica

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}]];
a[n_] := b[n-1, 0, 0];
Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Aug 14 2017, translated from Maple *)

Crossrefs

Column k=5 of A264909.

Sequence in context: A098663 A265085 A158828 * A196471 A265279 A034164

Adjacent sequences: A264907 A264908 A264909 * A264911 A264912 A264913

Keyword

nonn

Author

Alois P. Heinz, Nov 28 2015

Status

approved