A241697 Number of Carlitz compositions of n with exactly seven descents.

21, 150, 688, 2561, 8253, 23930, 64030, 160539, 381379, 865676, 1889308, 3984311, 8151834, 16234161, 31554397, 59999259, 111824744, 204629354, 368190175, 652238928, 1138836325, 1961870558, 3337496363, 5611246209, 9330350788, 15353900381, 25019429935

Offset

21,1

Comments

No two adjacent parts of a Carlitz composition are equal.

Links

Alois P. Heinz, Table of n, a(n) for n = 21..1000

Maple

b:= proc(n, i) option remember; `if`(n=0, 1,
       convert(series(add(`if`(i=j, 0, b(n-j, j)*
      `if`(j<i, x, 1)), j=1..n), x, 8), polynom))
    end:
a:= n-> coeff(b(n, 0), x, 7):
seq(a(n), n=21..50);

Crossrefs

Column k=7 of A241701.

Sequence in context: A253459 A041850 A239123 * A358994 A239569 A219599

Adjacent sequences: A241694 A241695 A241696 * A241698 A241699 A241700

Keyword

nonn

Author

Alois P. Heinz, Apr 27 2014

Status

approved