A186767 - cp's OEIS frontend

A186767 Number of permutations of {1,2,...,n} having no nonincreasing odd cycles. A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1) . A cycle is said to be odd if it has an odd number of entries.

n	a(n)
0	1
1	1
2	2
3	5
4	20
5	77
6	472
7	2585
8	21968
9	157113
10	1724064
11	15229645
12	204738624
13	2151199429
14	34194201472
15	416221515169
16	7631627843840
17	105565890206193
18	2192501224174080
19	33962775502534165
20	787900686999286784
21	13509825183288167869

[1, 1, 2, 5, 20, 77, 472, 2585, 21968, 157113, 1724064, 15229645, 204738624, 2151199429, 34194201472, 416221515169, 7631627843840, 105565890206193, 2192501224174080, 33962775502534165, 787900686999286784, 13509825183288167869]

cp's OEIS Frontend

A186767 Number of permutations of {1,2,...,n} having no nonincreasing odd cycles. A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1) . A cycle is said to be odd if it has an odd number of entries.

Table of values

List of values