A244721 Number of compositions of n with exactly 9 transitions between different parts.

2, 28, 210, 1158, 5112, 19206, 63494, 189092, 516528, 1310128, 3119942, 7027866, 15082152, 30994832, 61292380, 117063670, 216690678, 389814504, 683256278, 1169346934, 1957831816, 3212249500, 5172450680, 8185057350, 12743907242, 19544000940, 29551096298

Offset: 15

Author

Joerg Arndt and Alois P. Heinz, Jul 04 2014

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 15..900

Crossrefs

Column k=9 of A238279.

Programs

Maple

b:= proc(n, v) option remember; `if`(n=0, [1, 0$9],
      add(`if`(v in [0, i], b(n-i, `if`(i<=n-i, i, -1)),
      [0, b(n-i, `if`(i<=n-i, i, -1))[1..9][]]), i=1..n))
    end:
a:= n-> b(n, 0)[10]:
seq(a(n), n=15..60);