A107761 - cp's OEIS frontend

A107761 Number of permutations of (1,3,5,7,9,...,2n-1) where every adjacent pair in the permutation are coprime.

n	a(n)
1	1
2	2
3	6
4	24
5	72
6	480
7	3600
8	9600
9	108000
10	1270080
11	4795200
12	74088000
13	768539520
14	4759413120
15	94182359040
16	1893397524480
17	11353661706240
18	122634632171520
19	3104438623534080
20	23063946114908160
21	664424069072117760

[1, 2, 6, 24, 72, 480, 3600, 9600, 108000, 1270080, 4795200, 74088000, 768539520, 4759413120, 94182359040, 1893397524480, 11353661706240, 122634632171520, 3104438623534080, 23063946114908160, 664424069072117760]

cp's OEIS Frontend

A107761 Number of permutations of (1,3,5,7,9,...,2n-1) where every adjacent pair in the permutation are coprime.

Table of values

List of values