A246567 - cp's OEIS frontend

A246567 a(n) = (sum_{k=0}^{n-1}C(n-1,k)^2C(-n-1,k)^2/(4k^2-1))/n, where C(x,k) refers to binomial(x,k).

n	a(n)
1	-1
2	1
3	9
4	61
5	587
6	7575
7	117485
8	2057365
9	39314175
10	802816213
11	17275712297
12	387886408443
13	9020881956707
14	216101556811603
15	5309497149531957
16	133334756362738885
17	3412887111988377575
18	88838285028658754625
19	2347236720247792005665
20	62849602943515066525633

[-1, 1, 9, 61, 587, 7575, 117485, 2057365, 39314175, 802816213, 17275712297, 387886408443, 9020881956707, 216101556811603, 5309497149531957, 133334756362738885, 3412887111988377575, 88838285028658754625, 2347236720247792005665, 62849602943515066525633]

cp's OEIS Frontend

A246567 a(n) = (sum_{k=0}^{n-1}C(n-1,k)^2C(-n-1,k)^2/(4k^2-1))/n, where C(x,k) refers to binomial(x,k).

Table of values

List of values

cp's OEIS Frontend

A246567 a(n) = (sum_{k=0}^{n-1}C(n-1,k)^2*C(-n-1,k)^2/(4*k^2-1))/n, where C(x,k) refers to binomial(x,k).

Table of values

List of values

A246567 a(n) = (sum_{k=0}^{n-1}C(n-1,k)^2C(-n-1,k)^2/(4k^2-1))/n, where C(x,k) refers to binomial(x,k).