A087099 - OEIS

A087099 as a simple table

n	a(n)
1	1
2	3
3	6
4	11
5	16
6	24
7	31
8	42
9	51
10	65
11	76
12	93
13	106
14	126
15	141
16	164
17	181
18	207
19	226
20	255
21	276
22	308
23	331
24	366
25	391
26	429
27	456
28	497
29	526
30	570
31	601
32	648
33	681
34	731
35	766
36	819
37	856
38	912
39	951
40	1010
41	1051
42	1113
43	1156
44	1221
45	1266
46	1334
47	1381
48	1452
49	1501
50	1575
51	1626

[1,3,6,11,16,24,31,42,51,65,76,93,106,126,141,164, 181,207,226,255,276,308,331,366,391,429,456,497, 526,570,601,648,681,731,766,819,856,912,951,1010, 1051,1113,1156,1221,1266,1334,1381,1452,1501,1575, 1626]