A272432 Number of ordered set partitions of {1,2,...,n} such that no part has the same size as any of its four immediate predecessors.

1, 1, 1, 7, 9, 31, 403, 757, 2873, 12607, 333051, 761377, 3699435, 16383121, 108710085, 4855474267, 28123899993, 241045678351, 2865769028107, 22701288941281, 238433702214659, 4399193720759677, 46157742163810905, 514035796837721671, 8889375296702138075

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..80

Crossrefs

Column k=4 of A261959.

Sequence in context: A032011 A272434 A272433 * A272431 A261961 A177030

Adjacent sequences: A272429 A272430 A272431 * A272433 A272434 A272435

Keyword

nonn

Author

Alois P. Heinz, Apr 29 2016

Status

approved