A222690 - OEIS

A222690 as a simple table

n	a(n)
1	1
2	0
3	0
4	0
5	3
6	0
7	3
8	4
9	8
10	0
11	4
12	18
13	32
14	50
15	0
16	8
17	56
18	220
19	420
20	216
21	0
22	10
23	237
24	664
25	3189
26	2050
27	1120
28	0
29	50
30	784
31	7248
32	29770
33	47696
34	32296
35	5440
36	0
37	66
38	3218
39	25642
40	288829
41	419562
42	723244
43	159672
44	27576
45	0
46	216
47	11152
48	298371
49	3056797
50	12765040
51	20259516

[1,0,0,0,3,0,3,4,8,0,4,18,32,50,0,8,56,220,420, 216,0,10,237,664,3189,2050,1120,0,50,784,7248, 29770,47696,32296,5440,0,66,3218,25642,288829, 419562,723244,159672,27576,0,216,11152,298371, 3056797,12765040,20259516]