A122774 - cp's OEIS frontend

A122774 Triangle of bifactorial numbers, n B m = (2(n-m)-1)!! (2(n-1))!! / (2(n-m))!!, read by rows.

n	a(n)
1	1
2	1
3	2
4	3
5	4
6	8
7	15
8	18
9	24
10	48
11	105
12	120
13	144
14	192
15	384
16	945
17	1050
18	1200
19	1440
20	1920
21	3840
22	10395
23	11340
24	12600
25	14400
26	17280
27	23040
28	46080
29	135135
30	145530
31	158760
32	176400
33	201600
34	241920
35	322560
36	645120

[1, 1, 2, 3, 4, 8, 15, 18, 24, 48, 105, 120, 144, 192, 384, 945, 1050, 1200, 1440, 1920, 3840, 10395, 11340, 12600, 14400, 17280, 23040, 46080, 135135, 145530, 158760, 176400, 201600, 241920, 322560, 645120]

cp's OEIS Frontend

A122774 Triangle of bifactorial numbers, n B m = (2(n-m)-1)!! (2(n-1))!! / (2(n-m))!!, read by rows.

Table of values

List of values