A000139 - cp's OEIS frontend

A000139 a(n) = 2(3n)! / ((2n+1)!(n+1)!).

n	a(n)
0	2
1	1
2	2
3	6
4	22
5	91
6	408
7	1938
8	9614
9	49335
10	260130
11	1402440
12	7702632
13	42975796
14	243035536
15	1390594458
16	8038677054
17	46892282815
18	275750636070
19	1633292229030
20	9737153323590
21	58392041019795
22	352044769046880
23	2132866978427640
24	12980019040145352
25	79319075627675556

[2, 1, 2, 6, 22, 91, 408, 1938, 9614, 49335, 260130, 1402440, 7702632, 42975796, 243035536, 1390594458, 8038677054, 46892282815, 275750636070, 1633292229030, 9737153323590, 58392041019795, 352044769046880, 2132866978427640, 12980019040145352, 79319075627675556]

cp's OEIS Frontend

A000139 a(n) = 2(3n)! / ((2n+1)!(n+1)!).

Table of values

List of values

cp's OEIS Frontend

A000139 a(n) = 2*(3*n)! / ((2*n+1)!*(n+1)!).

Table of values

List of values

A000139 a(n) = 2(3n)! / ((2n+1)!(n+1)!).