A305823 Total number of blocks in all set partitions of [n] with alternating parity of elements.

0, 1, 3, 8, 20, 53, 136, 383, 1067, 3292, 10162, 34586, 118332, 441898, 1660947, 6745710, 27575425, 120801230, 532530170, 2499230441, 11800052796, 58992236094, 296630364605, 1572128197439, 8378539879636, 46882666240016, 263735138346443, 1552510947814406

Offset

0,3

Links

Table of n, a(n) for n=0..27.

Wikipedia, Partition of a set

Formula

a(n) = Sum_{k=0..n} k * A274581(n,k).

Crossrefs

Cf. A274581.

Sequence in context: A294407 A295346 A027220 * A333679 A230953 A026995

Adjacent sequences: A305820 A305821 A305822 * A305824 A305825 A305826

Keyword

nonn

Author

Alois P. Heinz, Jun 10 2018

Status

approved