A109813 - cp's OEIS frontend

A109813 Number of permutations of (the positive integers <= n and coprime to n), where each element of the permutations is coprime to its adjacent elements.

n	a(n)
1	1
2	1
3	2
4	2
5	12
6	2
7	72
8	24
9	144
10	12
11	22032
12	24
13	476928
14	480
15	1728
16	9600
17	805146624
18	720
19	36481536000
20	30240
21	1728000
22	312000
23	192859121664000
24	40320
25	2159795404800
26	46293120
27	249684249600
28	58423680

[1, 1, 2, 2, 12, 2, 72, 24, 144, 12, 22032, 24, 476928, 480, 1728, 9600, 805146624, 720, 36481536000, 30240, 1728000, 312000, 192859121664000, 40320, 2159795404800, 46293120, 249684249600, 58423680]

cp's OEIS Frontend

A109813 Number of permutations of (the positive integers <= n and coprime to n), where each element of the permutations is coprime to its adjacent elements.

Table of values

List of values