A202689 - cp's OEIS frontend

A202689 a(n) = (2n)! * (n+1)! / 2^(2n).

n	a(n)
0	1
1	1
2	9
3	270
4	18900
5	2551500
6	589396500
7	214540326000
8	115851776040000
9	88626608670600000
10	92614806060777000000
11	128364121200236922000000
12	230285233433225038068000000
13	523898906060586961604700000000
14	1485253398681764036149324500000000

[1, 1, 9, 270, 18900, 2551500, 589396500, 214540326000, 115851776040000, 88626608670600000, 92614806060777000000, 128364121200236922000000, 230285233433225038068000000, 523898906060586961604700000000, 1485253398681764036149324500000000]

cp's OEIS Frontend

A202689 a(n) = (2n)! * (n+1)! / 2^(2n).

Table of values

List of values