A320764 Number of ordered set partitions of [n] where the maximal block size equals eight.

1, 18, 360, 7260, 152460, 3361644, 78041964, 1908389340, 49118959890, 1328964080730, 37738620245898, 1122927974067042, 34953464391146730, 1136306352798186570, 38520124906043253330, 1359621561034260858906, 49896547074800880656202, 1901350452285623246965200

Offset

8,2

Links

Alois P. Heinz, Table of n, a(n) for n = 8..425

Formula

E.g.f.: 1/(1-Sum_{i=1..8} x^i/i!) - 1/(1-Sum_{i=1..7} x^i/i!).

a(n) = A276928(n) - A276927(n).

Maple

b:= proc(n, k) option remember; `if`(n=0, 1, add(
      b(n-i, k)*binomial(n, i), i=1..min(n, k)))
    end:
a:= n-> (k-> b(n, k) -b(n, k-1))(8):
seq(a(n), n=8..25);

Crossrefs

Column k=8 of A276922.

Cf. A276927, A276928.

Sequence in context: A230348 A366684 A182609 * A086502 A259459 A099276

Adjacent sequences: A320761 A320762 A320763 * A320765 A320766 A320767

Keyword

nonn

Author

Alois P. Heinz, Oct 20 2018

Status

approved