A027318 - cp's OEIS frontend

A027318 a(n) = Sum_{k=0..m-3} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.

n	a(n)
3	1
4	42
5	420
6	3786
7	33648
8	297940
9	2633872
10	23265744
11	205446960
12	1814136746
13	16021697220
14	141535810130
15	1250763720312
16	11057433981126
17	97794407702052
18	865284559977150
19	7659315417653664
20	67827407480624862
21	600898634852988364
22	5325658497658529790

[1, 42, 420, 3786, 33648, 297940, 2633872, 23265744, 205446960, 1814136746, 16021697220, 141535810130, 1250763720312, 11057433981126, 97794407702052, 865284559977150, 7659315417653664, 67827407480624862, 600898634852988364, 5325658497658529790]

cp's OEIS Frontend

A027318 a(n) = Sum_{k=0..m-3} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.

Table of values

List of values