A002872 - cp's OEIS frontend

A002872 Number of partitions of {1..2n} that are invariant under a permutation consisting of n 2-cycles.

n	a(n)
0	1
1	2
2	7
3	31
4	164
5	999
6	6841
7	51790
8	428131
9	3827967
10	36738144
11	376118747
12	4086419601
13	46910207114
14	566845074703
15	7186474088735
16	95318816501420
17	1319330556537631
18	19013488408858761
19	284724852032757686
20	4422344774431494155
21	71125541977466879231

[1, 2, 7, 31, 164, 999, 6841, 51790, 428131, 3827967, 36738144, 376118747, 4086419601, 46910207114, 566845074703, 7186474088735, 95318816501420, 1319330556537631, 19013488408858761, 284724852032757686, 4422344774431494155, 71125541977466879231]

cp's OEIS Frontend

A002872 Number of partitions of {1..2n} that are invariant under a permutation consisting of n 2-cycles.

Table of values

List of values