A133922 - cp's OEIS frontend

A133922 a(n) is number of permutations (p(1),p(2),p(3),...,p(n)) of (1,2,3,...,n) such that p(k) is coprime to p(n+1-k) for k = all positive integers <= n.

n	a(n)
1	1
2	2
3	2
4	16
5	16
6	192
7	192
8	6912
9	4608
10	230400
11	230400
12	11612160
13	11612160
14	1199923200
15	588349440
16	98594979840
17	98594979840
18	11076328488960
19	11076328488960
20	2102897147904000
21	1076597725593600
22	331238941183180800
23	331238941183180800
24	66325953940291584000
25	56326771107377971200

[1, 2, 2, 16, 16, 192, 192, 6912, 4608, 230400, 230400, 11612160, 11612160, 1199923200, 588349440, 98594979840, 98594979840, 11076328488960, 11076328488960, 2102897147904000, 1076597725593600, 331238941183180800, 331238941183180800, 66325953940291584000, 56326771107377971200]

cp's OEIS Frontend

A133922 a(n) is number of permutations (p(1),p(2),p(3),...,p(n)) of (1,2,3,...,n) such that p(k) is coprime to p(n+1-k) for k = all positive integers <= n.

Table of values

List of values