A333315 - cp's OEIS frontend

A333315 a(n) = Sum_{k=1..n} phi(prime(k)-1), where phi is the Euler totient function (A000005).

n	a(n)
1	1
2	2
3	4
4	6
5	10
6	14
7	22
8	28
9	38
10	50
11	58
12	70
13	86
14	98
15	120
16	144
17	172
18	188
19	208
20	232
21	256
22	280
23	320
24	360
25	392
26	432
27	464
28	516
29	552
30	600
31	636
32	684
33	748
34	792
35	864
36	904
37	952
38	1006
39	1088
40	1172
41	1260
42	1308
43	1380
44	1444
45	1528
46	1588
47	1636
48	1708
49	1820
50	1892
51	2004
52	2100
53	2164

[1, 2, 4, 6, 10, 14, 22, 28, 38, 50, 58, 70, 86, 98, 120, 144, 172, 188, 208, 232, 256, 280, 320, 360, 392, 432, 464, 516, 552, 600, 636, 684, 748, 792, 864, 904, 952, 1006, 1088, 1172, 1260, 1308, 1380, 1444, 1528, 1588, 1636, 1708, 1820, 1892, 2004, 2100, 2164]

cp's OEIS Frontend

A333315 a(n) = Sum_{k=1..n} phi(prime(k)-1), where phi is the Euler totient function (A000005).

Table of values

List of values