A006882 - cp's OEIS frontend

A006882 Double factorials n!!: a(n) = n*a(n-2) for n > 1, a(0) = a(1) = 1.

n	a(n)
0	1
1	1
2	2
3	3
4	8
5	15
6	48
7	105
8	384
9	945
10	3840
11	10395
12	46080
13	135135
14	645120
15	2027025
16	10321920
17	34459425
18	185794560
19	654729075
20	3715891200
21	13749310575
22	81749606400
23	316234143225
24	1961990553600
25	7905853580625
26	51011754393600
27	213458046676875
28	1428329123020800

[1, 1, 2, 3, 8, 15, 48, 105, 384, 945, 3840, 10395, 46080, 135135, 645120, 2027025, 10321920, 34459425, 185794560, 654729075, 3715891200, 13749310575, 81749606400, 316234143225, 1961990553600, 7905853580625, 51011754393600, 213458046676875, 1428329123020800]

cp's OEIS Frontend

A006882 Double factorials n!!: a(n) = n*a(n-2) for n > 1, a(0) = a(1) = 1.

Table of values

List of values