A123144 - cp's OEIS frontend

A123144 a(1) = 1, a(n) = a(n-1) if n = 1 (mod 3), otherwise n*a(n-1).

n	a(n)
1	1
2	2
3	6
4	6
5	30
6	180
7	180
8	1440
9	12960
10	12960
11	142560
12	1710720
13	1710720
14	23950080
15	359251200
16	359251200
17	6107270400
18	109930867200
19	109930867200
20	2198617344000
21	46170964224000
22	46170964224000
23	1061932177152000
24	25486372251648000
25	25486372251648000

[1, 2, 6, 6, 30, 180, 180, 1440, 12960, 12960, 142560, 1710720, 1710720, 23950080, 359251200, 359251200, 6107270400, 109930867200, 109930867200, 2198617344000, 46170964224000, 46170964224000, 1061932177152000, 25486372251648000, 25486372251648000]

cp's OEIS Frontend

A123144 a(1) = 1, a(n) = a(n-1) if n = 1 (mod 3), otherwise n*a(n-1).

Table of values

List of values