A245769 - cp's OEIS frontend

A245769 a(n) = Sum_{k=0..n} C(n, k)C(n+k, k)/(2k-1), where C(n, k) denotes the binomial coefficient n!/(k!(n-k)!).

n	a(n)
0	-1
1	1
2	7
3	25
4	87
5	329
6	1359
7	6001
8	27759
9	132689
10	649815
11	3242377
12	16421831
13	84196761
14	436129183
15	2278835681
16	11996748255
17	63568974241
18	338777252263
19	1814623238137
20	9763917858359
21	52750451120361
22	286036294786287
23	1556185889290065
24	8492182185653327
25	46471113779766769

[-1, 1, 7, 25, 87, 329, 1359, 6001, 27759, 132689, 649815, 3242377, 16421831, 84196761, 436129183, 2278835681, 11996748255, 63568974241, 338777252263, 1814623238137, 9763917858359, 52750451120361, 286036294786287, 1556185889290065, 8492182185653327, 46471113779766769]

cp's OEIS Frontend

A245769 a(n) = Sum_{k=0..n} C(n, k)C(n+k, 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

A245769 a(n) = Sum_{k=0..n} C(n, k)*C(n+k, k)/(2k-1), where C(n, k) denotes the binomial coefficient n!/(k!*(n-k)!).

Table of values

List of values

A245769 a(n) = Sum_{k=0..n} C(n, k)C(n+k, k)/(2k-1), where C(n, k) denotes the binomial coefficient n!/(k!(n-k)!).