A374707 - OEIS

A374707 as a simple table

n	a(n)
0	1
1	3
2	6
3	10
4	15
5	21
6	28
7	36
8	45
9	55
10	66
11	78
12	90
13	104
14	119
15	135
16	151
17	169
18	188
19	208
20	229
21	251
22	274
23	298
24	322
25	348
26	375
27	402
28	431
29	461
30	492
31	524
32	556
33	590
34	623
35	659
36	695
37	733
38	772
39	811
40	851
41	893
42	936
43	980
44	1025
45	1071
46	1118
47	1166
48	1213
49	1263
50	1314
51	1365
52	1418
53	1471
54	1525
55	1580
56	1637
57	1695
58	1753

[1,3,6,10,15,21,28,36,45,55,66,78,90,104,119,135, 151,169,188,208,229,251,274,298,322,348,375,402, 431,461,492,524,556,590,623,659,695,733,772,811, 851,893,936,980,1025,1071,1118,1166,1213,1263, 1314,1365,1418,1471,1525,1580,1637,1695,1753]