A085139 - cp's OEIS frontend

A085139 a(n) = Sum_{i=0..n-1} (1 + (-1)^(n-1-i))/2 * Sum_{j=0..i} a(j)*a(i-j) for n > 0, with a(0) = 1.

n	a(n)
0	1
1	1
2	2
3	6
4	18
5	58
6	194
7	670
8	2370
9	8546
10	31298
11	116102
12	435346
13	1647418
14	6283394
15	24130174
16	93226242
17	362098050
18	1413098370
19	5538138182
20	21788069266
21	86016385274
22	340655956802
23	1353023683486
24	5388230857538
25	21510345134178

[1, 1, 2, 6, 18, 58, 194, 670, 2370, 8546, 31298, 116102, 435346, 1647418, 6283394, 24130174, 93226242, 362098050, 1413098370, 5538138182, 21788069266, 86016385274, 340655956802, 1353023683486, 5388230857538, 21510345134178]

cp's OEIS Frontend

A085139 a(n) = Sum_{i=0..n-1} (1 + (-1)^(n-1-i))/2 * Sum_{j=0..i} a(j)*a(i-j) for n > 0, with a(0) = 1.

Table of values

List of values