A374426 - cp's OEIS frontend

A374426 a(n) = n*(n + 1)/2 + pi(n), where pi(n) = A000720(n) is the prime counting function.

n	a(n)
1	1
2	4
3	8
4	12
5	18
6	24
7	32
8	40
9	49
10	59
11	71
12	83
13	97
14	111
15	126
16	142
17	160
18	178
19	198
20	218
21	239
22	261
23	285
24	309
25	334
26	360
27	387
28	415
29	445
30	475
31	507
32	539
33	572
34	606
35	641
36	677
37	715
38	753
39	792
40	832
41	874
42	916
43	960
44	1004
45	1049
46	1095
47	1143
48	1191
49	1240
50	1290
51	1341
52	1393
53	1447

[1, 4, 8, 12, 18, 24, 32, 40, 49, 59, 71, 83, 97, 111, 126, 142, 160, 178, 198, 218, 239, 261, 285, 309, 334, 360, 387, 415, 445, 475, 507, 539, 572, 606, 641, 677, 715, 753, 792, 832, 874, 916, 960, 1004, 1049, 1095, 1143, 1191, 1240, 1290, 1341, 1393, 1447]

cp's OEIS Frontend

A374426 a(n) = n*(n + 1)/2 + pi(n), where pi(n) = A000720(n) is the prime counting function.

Table of values

List of values