A015741 - OEIS

A015741 as a simple table

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	1
7	1
8	1
9	2
10	2
11	3
12	3
13	4
14	5
15	6
16	8
17	9
18	12
19	14
20	17
21	21
22	24
23	29
24	34
25	40
26	47
27	55
28	65
29	75
30	88
31	102
32	118
33	137
34	157
35	181
36	208
37	238
38	272
39	311
40	355
41	404
42	460
43	522
44	592
45	671
46	758
47	856
48	966
49	1088
50	1224
51	1377
52	1546
53	1734
54	1944

[0,0,0,0,0,1,1,1,2,2,3,3,4,5,6,8,9,12,14,17,21,24, 29,34,40,47,55,65,75,88,102,118,137,157,181,208, 238,272,311,355,404,460,522,592,671,758,856,966, 1088,1224,1377,1546,1734,1944]