A061786 - OEIS

A061786 as a simple table

n	a(n)
1	1
2	3
3	6
4	10
5	15
6	21
7	27
8	34
9	42
10	52
11	61
12	72
13	83
14	94
15	108
16	122
17	135
18	151
19	165
20	183
21	200
22	218
23	234
24	254
25	275
26	296
27	317
28	339
29	361
30	387
31	409
32	434
33	460
34	484
35	512
36	542
37	570
38	598
39	627
40	661
41	689
42	722
43	753
44	784
45	821
46	854
47	888
48	925
49	960
50	998
51	1036
52	1075
53	1109
54	1148

[1,3,6,10,15,21,27,34,42,52,61,72,83,94,108,122, 135,151,165,183,200,218,234,254,275,296,317,339, 361,387,409,434,460,484,512,542,570,598,627,661, 689,722,753,784,821,854,888,925,960,998,1036,1075, 1109,1148]