A034856 - cp's OEIS frontend

A034856 a(n) = binomial(n+1, 2) + n - 1 = n*(n+3)/2 - 1.

n	a(n)
1	1
2	4
3	8
4	13
5	19
6	26
7	34
8	43
9	53
10	64
11	76
12	89
13	103
14	118
15	134
16	151
17	169
18	188
19	208
20	229
21	251
22	274
23	298
24	323
25	349
26	376
27	404
28	433
29	463
30	494
31	526
32	559
33	593
34	628
35	664
36	701
37	739
38	778
39	818
40	859
41	901
42	944
43	988
44	1033
45	1079
46	1126
47	1174
48	1223
49	1273
50	1324
51	1376
52	1429
53	1483

[1, 4, 8, 13, 19, 26, 34, 43, 53, 64, 76, 89, 103, 118, 134, 151, 169, 188, 208, 229, 251, 274, 298, 323, 349, 376, 404, 433, 463, 494, 526, 559, 593, 628, 664, 701, 739, 778, 818, 859, 901, 944, 988, 1033, 1079, 1126, 1174, 1223, 1273, 1324, 1376, 1429, 1483]

cp's OEIS Frontend

A034856 a(n) = binomial(n+1, 2) + n - 1 = n*(n+3)/2 - 1.

Table of values

List of values