A246065 - cp's OEIS frontend

A246065 a(n) = Sum_{k=0..n}C(n,k)^2C(2k,k)/(2k-1), where C(n,k) denotes the binomial coefficient n!/(k!(n-k)!).

n	a(n)
0	-1
1	1
2	9
3	39
4	177
5	927
6	5463
7	34857
8	234657
9	1641471
10	11820135
11	87080265
12	653499135
13	4979882385
14	38441107305
15	300027646647
16	2364113123073
17	18784242756927
18	150351698420247
19	1211310469545081
20	9816017765368671
21	79963826730913809
22	654504197331971961
23	5380270242617370951

[-1, 1, 9, 39, 177, 927, 5463, 34857, 234657, 1641471, 11820135, 87080265, 653499135, 4979882385, 38441107305, 300027646647, 2364113123073, 18784242756927, 150351698420247, 1211310469545081, 9816017765368671, 79963826730913809, 654504197331971961, 5380270242617370951]

cp's OEIS Frontend

A246065 a(n) = Sum_{k=0..n}C(n,k)^2C(2k,k)/(2k-1), where C(n,k) denotes the binomial coefficient n!/(k!(n-k)!).

Table of values

List of values

cp's OEIS Frontend

A246065 a(n) = Sum_{k=0..n}C(n,k)^2*C(2k,k)/(2k-1), where C(n,k) denotes the binomial coefficient n!/(k!*(n-k)!).

Table of values

List of values

A246065 a(n) = Sum_{k=0..n}C(n,k)^2C(2k,k)/(2k-1), where C(n,k) denotes the binomial coefficient n!/(k!(n-k)!).