A080107 - cp's OEIS frontend

A080107 Number of fixed points of permutation of SetPartitions under {1,2,...,n}->{n,n-1,...,1}. Number of symmetric arrangements of non-attacking rooks on upper half of n X n chessboard.

n	a(n)
0	1
1	1
2	2
3	3
4	7
5	12
6	31
7	59
8	164
9	339
10	999
11	2210
12	6841
13	16033
14	51790
15	127643
16	428131
17	1103372
18	3827967
19	10269643
20	36738144
21	102225363
22	376118747
23	1082190554
24	4086419601
25	12126858113
26	46910207114
27	143268057587
28	566845074703
29	1778283994284
30	7186474088735

[1, 1, 2, 3, 7, 12, 31, 59, 164, 339, 999, 2210, 6841, 16033, 51790, 127643, 428131, 1103372, 3827967, 10269643, 36738144, 102225363, 376118747, 1082190554, 4086419601, 12126858113, 46910207114, 143268057587, 566845074703, 1778283994284, 7186474088735]

cp's OEIS Frontend

A080107 Number of fixed points of permutation of SetPartitions under {1,2,...,n}->{n,n-1,...,1}. Number of symmetric arrangements of non-attacking rooks on upper half of n X n chessboard.

Table of values

List of values