A253665 - cp's OEIS frontend

A253665 a(n) = 2^n*n!/(floor(n/2)!)^2.

n	a(n)
0	1
1	2
2	8
3	48
4	96
5	960
6	1280
7	17920
8	17920
9	322560
10	258048
11	5677056
12	3784704
13	98402304
14	56229888
15	1686896640
16	843448320
17	28677242880
18	12745441280
19	484326768640
20	193730707456
21	8136689713152
22	2958796259328
23	136104627929088
24	45368209309696
25	2268410465484800

[1, 2, 8, 48, 96, 960, 1280, 17920, 17920, 322560, 258048, 5677056, 3784704, 98402304, 56229888, 1686896640, 843448320, 28677242880, 12745441280, 484326768640, 193730707456, 8136689713152, 2958796259328, 136104627929088, 45368209309696, 2268410465484800]

cp's OEIS Frontend

A253665 a(n) = 2^n*n!/(floor(n/2)!)^2.

Table of values

List of values