A336009 - cp's OEIS frontend

A336009 a(0) = ... = a(3) = 1; a(n) = Sum_{k=0..n-4} binomial(n-4,k) * a(k) * a(n-k-4).

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	2
6	4
7	8
8	16
9	34
10	82
11	226
12	678
13	2108
14	6892
15	23948
16	88532
17	344816
18	1401200
19	5925000
20	26146360
21	120743496
22	582606552
23	2926675112
24	15259183112
25	82458502624
26	461577781968
27	2674216518016
28	16013654472352
29	98968416103968
30	630595248710144

[1, 1, 1, 1, 1, 2, 4, 8, 16, 34, 82, 226, 678, 2108, 6892, 23948, 88532, 344816, 1401200, 5925000, 26146360, 120743496, 582606552, 2926675112, 15259183112, 82458502624, 461577781968, 2674216518016, 16013654472352, 98968416103968, 630595248710144]

cp's OEIS Frontend

A336009 a(0) = ... = a(3) = 1; a(n) = Sum_{k=0..n-4} binomial(n-4,k) * a(k) * a(n-k-4).

Table of values

List of values