A263807 - OEIS

A263807 as a simple table

n	a(n)
0	1
1	3
2	6
3	11
4	17
5	25
6	34
7	45
8	57
9	71
10	86
11	103
12	121
13	141
14	162
15	185
16	209
17	235
18	262
19	291
20	321
21	353
22	386
23	421
24	457
25	495
26	534
27	575
28	617
29	661
30	706
31	753
32	801
33	851
34	902
35	955
36	1009
37	1065
38	1122
39	1181
40	1241
41	1303
42	1366
43	1431
44	1497
45	1565
46	1634
47	1705
48	1777
49	1851
50	1926

[1,3,6,11,17,25,34,45,57,71,86,103,121,141,162, 185,209,235,262,291,321,353,386,421,457,495,534, 575,617,661,706,753,801,851,902,955,1009,1065, 1122,1181,1241,1303,1366,1431,1497,1565,1634,1705, 1777,1851,1926]