A180662 - OEIS

A180662 as a simple table

n	a(n)
0	0
1	0
2	1
3	0
4	1
5	2
6	0
7	1
8	2
9	6
10	0
11	1
12	2
13	6
14	15
15	0
16	1
17	2
18	6
19	15
20	40
21	0
22	1
23	2
24	6
25	15
26	40
27	104
28	0
29	1
30	2
31	6
32	15
33	40
34	104
35	273
36	0
37	1
38	2
39	6
40	15
41	40
42	104
43	273
44	714
45	0
46	1
47	2
48	6
49	15
50	40
51	104
52	273
53	714
54	1870
55	0
56	1
57	2
58	6
59	15
60	40
61	104
62	273
63	714
64	1870
65	4895

[0,0,1,0,1,2,0,1,2,6,0,1,2,6,15,0,1,2,6,15,40,0,1, 2,6,15,40,104,0,1,2,6,15,40,104,273,0,1,2,6,15,40, 104,273,714,0,1,2,6,15,40,104,273,714,1870,0,1,2, 6,15,40,104,273,714,1870,4895]