A090580 - OEIS

A090580 as a simple table

n	a(n)
1	1
2	5
3	15
4	35
5	70
6	126
7	210
8	330
9	495
10	714
11	992
12	1330
13	1725
14	2170
15	2654
16	3162
17	3675
18	4170
19	4620
20	4998
21	5283
22	5460
23	5520
24	5460
25	5283
26	4998
27	4620
28	4170
29	3675
30	3162
31	2654
32	2170
33	1725
34	1330
35	992
36	714
37	495
38	330
39	210
40	126
41	70
42	35
43	15
44	5
45	1

[1,5,15,35,70,126,210,330,495,714,992,1330,1725, 2170,2654,3162,3675,4170,4620,4998,5283,5460,5520, 5460,5283,4998,4620,4170,3675,3162,2654,2170,1725, 1330,992,714,495,330,210,126,70,35,15,5,1]