A161581 - cp's OEIS frontend

A161581 a(n) = (3n)!/(n!(n+1)!(n+2)!).

n	a(n)
3	21
4	231
5	3003
6	43758
7	692835
8	11685817
9	207157665
10	3823000545
11	72931087320
12	1430571328200
13	28734046963560
14	589047962752980
15	12292044987448215
16	260543149635912165
17	5599392250947235125
18	121830987186399315825

[21, 231, 3003, 43758, 692835, 11685817, 207157665, 3823000545, 72931087320, 1430571328200, 28734046963560, 589047962752980, 12292044987448215, 260543149635912165, 5599392250947235125, 121830987186399315825]

cp's OEIS Frontend

A161581 a(n) = (3n)!/(n!(n+1)!(n+2)!).

Table of values

List of values