A179100 - cp's OEIS frontend

A179100 a(n) = (1/n) * Sum_{k=0..n-1} (8k+5) T_k^2, where T_0, T_1, ... are central trinomial coefficients given by A002426.

n	a(n)
1	5
2	9
3	69
4	407
5	2997
6	22005
7	169389
8	1325889
9	10573677
10	85386881
11	697013325
12	5739021051
13	47599593941
14	397234035333
15	3332690347437
16	28089543969855
17	237711099004461
18	2018856328439841
19	17200553934626253
20	146966002696538271

[5, 9, 69, 407, 2997, 22005, 169389, 1325889, 10573677, 85386881, 697013325, 5739021051, 47599593941, 397234035333, 3332690347437, 28089543969855, 237711099004461, 2018856328439841, 17200553934626253, 146966002696538271]

cp's OEIS Frontend

A179100 a(n) = (1/n) * Sum_{k=0..n-1} (8k+5) T_k^2, where T_0, T_1, ... are central trinomial coefficients given by A002426.

Table of values

List of values