A000891 - cp's OEIS frontend

A000891 a(n) = (2n)!(2n+1)! / (n! (n+1)!)^2.

n	a(n)
0	1
1	3
2	20
3	175
4	1764
5	19404
6	226512
7	2760615
8	34763300
9	449141836
10	5924217936
11	79483257308
12	1081724803600
13	14901311070000
14	207426250094400
15	2913690606794775
16	41255439318353700
17	588272005095043500

[1, 3, 20, 175, 1764, 19404, 226512, 2760615, 34763300, 449141836, 5924217936, 79483257308, 1081724803600, 14901311070000, 207426250094400, 2913690606794775, 41255439318353700, 588272005095043500]

cp's OEIS Frontend

A000891 a(n) = (2n)!(2n+1)! / (n! (n+1)!)^2.

Table of values

List of values

cp's OEIS Frontend

A000891 a(n) = (2*n)!*(2*n+1)! / (n! * (n+1)!)^2.

Table of values

List of values

A000891 a(n) = (2n)!(2n+1)! / (n! (n+1)!)^2.