A186765 - cp's OEIS frontend

A186765 Number of permutations of {1,2,...,n} having no increasing even 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 even if it has an even number of entries.

n	a(n)
0	1
1	1
2	1
3	3
4	14
5	70
6	419
7	2933
8	23421
9	210789
10	2108144
11	23189584
12	278279165
13	3617629145
14	50646737049
15	759701055735
16	12155215581362
17	206638664883154
18	3719496008830391
19	70670424167777429
20	1413408484443295197
21	29681578173309199137
22	652994719769134284068

[1, 1, 1, 3, 14, 70, 419, 2933, 23421, 210789, 2108144, 23189584, 278279165, 3617629145, 50646737049, 759701055735, 12155215581362, 206638664883154, 3719496008830391, 70670424167777429, 1413408484443295197, 29681578173309199137, 652994719769134284068]

cp's OEIS Frontend

A186765 Number of permutations of {1,2,...,n} having no increasing even 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 even if it has an even number of entries.

Table of values

List of values