A377985 - cp's OEIS frontend

A377985 a(n) = 2*n - phi(A003961(n)), where phi is Euler totient function and A003961 is fully multiplicative function with a(prime(i)) = prime(i+1).

n	a(n)
1	1
2	2
3	2
4	2
5	4
6	4
7	4
8	-2
9	-2
10	8
11	10
12	0
13	10
14	8
15	6
16	-22
17	16
18	-4
19	16
20	4
21	2
22	20
23	18
24	-24
25	8
26	20
27	-46
28	-4
29	28
30	12
31	26
32	-98
33	18
34	32
35	10
36	-48
37	34
38	32
39	14
40	-28
41	40
42	4
43	40
44	16
45	-30
46	36
47	42
48	-120
49	-12
50	16
51	30
52	8
53	48
54	-92
55	38
56	-68
57	26
58	56
59	58
60	-24
61	56
62	52
63	-74
64	-358
65	34
66	36
67	64
68	28
69	26
70	20
71	70
72	-216
73	68
74	68
75	-18
76	20
77	34
78	28

[1, 2, 2, 2, 4, 4, 4, -2, -2, 8, 10, 0, 10, 8, 6, -22, 16, -4, 16, 4, 2, 20, 18, -24, 8, 20, -46, -4, 28, 12, 26, -98, 18, 32, 10, -48, 34, 32, 14, -28, 40, 4, 40, 16, -30, 36, 42, -120, -12, 16, 30, 8, 48, -92, 38, -68, 26, 56, 58, -24, 56, 52, -74, -358, 34, 36, 64, 28, 26, 20, 70, -216, 68, 68, -18, 20, 34, 28]

cp's OEIS Frontend

A377985 a(n) = 2*n - phi(A003961(n)), where phi is Euler totient function and A003961 is fully multiplicative function with a(prime(i)) = prime(i+1).

Table of values

List of values