A351938 - cp's OEIS frontend

A351938 a(0) = 1; a(n) = -a(n-1) + 2 * Sum_{k=0..floor((n-1)/2)} a(k) * a(n-2*k-1).

n	a(n)
0	1
1	1
2	1
3	3
4	5
5	9
6	17
7	35
8	65
9	125
10	241
11	463
12	885
13	1701
14	3265
15	6271
16	12033
17	23105
18	44353
19	85147
20	163445
21	313777
22	602353
23	1156339
24	2219809
25	4261389
26	8180561
27	15704215
28	30147333
29	57873821
30	111100225
31	213278943
32	409431169
33	785984353
34	1508852673
35	2896541859

[1, 1, 1, 3, 5, 9, 17, 35, 65, 125, 241, 463, 885, 1701, 3265, 6271, 12033, 23105, 44353, 85147, 163445, 313777, 602353, 1156339, 2219809, 4261389, 8180561, 15704215, 30147333, 57873821, 111100225, 213278943, 409431169, 785984353, 1508852673, 2896541859]

cp's OEIS Frontend

A351938 a(0) = 1; a(n) = -a(n-1) + 2 * Sum_{k=0..floor((n-1)/2)} a(k) * a(n-2*k-1).

Table of values

List of values