A222311 - OEIS

A222311 as a simple table

n	a(n)
1	1
2	2
3	3
4	6
5	5
6	15
7	105
8	70
9	1
10	5
11	33
12	55
13	65
14	273
15	1001
16	1430
17	17
18	17
19	969
20	4845
21	1785
22	6545
23	37145
24	81719
25	17
26	1105
27	3553
28	969969
29	672945
30	81345
31	955049953
32	66786710
33	33
34	561
35	385
36	6545
37	6105
38	657305
39	15873
40	8544965
41	1353
42	268345
43	61705
44	329681
45	650793
46	24173705985
47	3065857
48	250538768183
49	561
50	33
51	21945

[1,2,3,6,5,15,105,70,1,5,33,55,65,273,1001,1430, 17,17,969,4845,1785,6545,37145,81719,17,1105,3553, 969969,672945,81345,955049953,66786710,33,561,385, 6545,6105,657305,15873,8544965,1353,268345,61705, 329681,650793,24173705985,3065857,250538768183, 561,33,21945]