A336023 - cp's OEIS frontend

A336023 a(0) = a(1) = a(2) = 1; a(n) = (1/2) * Sum_{k=0..n-2} binomial(n-2,k) * a(k) * a(n-k-2).

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	4
6	9
7	24
8	73
9	241
10	881
11	3526
12	15252
13	70989
14	354454
15	1887349
16	10674773
17	63936181
18	404240736
19	2690174976
20	18798077227
21	137612318374
22	1053181689299
23	8410678868749
24	69966341141373
25	605313810207096
26	5438284743262816
27	50668461879077851

[1, 1, 1, 1, 2, 4, 9, 24, 73, 241, 881, 3526, 15252, 70989, 354454, 1887349, 10674773, 63936181, 404240736, 2690174976, 18798077227, 137612318374, 1053181689299, 8410678868749, 69966341141373, 605313810207096, 5438284743262816, 50668461879077851]

cp's OEIS Frontend

A336023 a(0) = a(1) = a(2) = 1; a(n) = (1/2) * Sum_{k=0..n-2} binomial(n-2,k) * a(k) * a(n-k-2).

Table of values

List of values