A023923 - OEIS

A023923 as a simple table

n	a(n)
0	1
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	0
11	24
12	0
13	0
14	0
15	0
16	0
17	0
18	0
19	0
20	132
21	0
22	0
23	0
24	132
25	0
26	0
27	440
28	0
29	0
30	0
31	0
32	990
33	0
34	0
35	2904
36	924
37	0
38	0
39	0
40	0
41	0
42	0
43	0
44	3984
45	0
46	0
47	0
48	2970
49	0
50	0
51	8184
52	0
53	0
54	0
55	0
56	12408
57	0
58	0
59	31152
60	7920
61	0
62	0
63	0
64	0
65	0
66	0
67	0
68	30360
69	0
70	0
71	0
72	19800
73	0
74	0
75	45144
76	0

[1,0,0,0,0,0,0,0,0,0,0,24,0,0,0,0,0,0,0,0,132,0,0, 0,132,0,0,440,0,0,0,0,990,0,0,2904,924,0,0,0,0,0, 0,0,3984,0,0,0,2970,0,0,8184,0,0,0,0,12408,0,0, 31152,7920,0,0,0,0,0,0,0,30360,0,0,0,19800,0,0, 45144,0]