A295864 - cp's OEIS frontend

A295864 a(n) = hypergeom([-n, -n], [1], 1) * n! / (floor(n/2)!)^2.

n	a(n)
0	1
1	2
2	12
3	120
4	420
5	7560
6	18480
7	480480
8	900900
9	30630600
10	46558512
11	1955457504
12	2498640144
13	124932007200
14	137680171200
15	7985449929600
16	7735904619300
17	510569704873800
18	441233078286000
19	32651247793164000
20	25467973278667920
21	2088373808850769440
22	1484298740174927040

[1, 2, 12, 120, 420, 7560, 18480, 480480, 900900, 30630600, 46558512, 1955457504, 2498640144, 124932007200, 137680171200, 7985449929600, 7735904619300, 510569704873800, 441233078286000, 32651247793164000, 25467973278667920, 2088373808850769440, 1484298740174927040]

cp's OEIS Frontend

A295864 a(n) = hypergeom([-n, -n], [1], 1) * n! / (floor(n/2)!)^2.

Table of values

List of values