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

Author

Alois P. Heinz, Apr 29 2016

Keywords

• nonn

Links

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

Crossrefs

Column k=4 of A261959.