A337247 - cp's OEIS frontend

A337247 a(n) = (Sum_{k=0..n-1} (-1)^k * (4k+1) * 160^(n-1-k) * C(2k,k) * Sum_{j=0..k} C(k,j) * C(k+2j,2j) * C(2j,j) * (-20)^(k-j)) / (n * C(2n,n)).

n	a(n)
2	25
3	809
4	23020
5	730325
6	27867142
7	1117643720
8	42658771456
9	1558395721085
10	57260792702050
11	2179584653311070
12	84835851591609400
13	3292250198848240760
14	126379831667243976400
15	4841030410501144484000
16	186842197443136622824960
17	7269291788529191112814925
18	283472902036823148786161530

[25, 809, 23020, 730325, 27867142, 1117643720, 42658771456, 1558395721085, 57260792702050, 2179584653311070, 84835851591609400, 3292250198848240760, 126379831667243976400, 4841030410501144484000, 186842197443136622824960, 7269291788529191112814925, 283472902036823148786161530]

cp's OEIS Frontend

A337247 a(n) = (Sum_{k=0..n-1} (-1)^k * (4k+1) * 160^(n-1-k) * C(2k,k) * Sum_{j=0..k} C(k,j) * C(k+2j,2j) * C(2j,j) * (-20)^(k-j)) / (n * C(2n,n)).

Table of values

List of values