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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A380354 a(n) = phi(2 + phi(3 + phi(5 + ... + phi(prime(n))))), where phi is Euler totient function (A000010).

Table of values

n a(n)
1 1
2 2
3 4
4 6
5 4
6 8
7 8
8 12
9 12
10 16
11 20
12 20
13 18
14 40
15 40
16 16
17 18
18 18
19 16
20 72
21 40
22 16
23 40
24 18
25 96
26 96
27 18
28 64
29 20
30 40
31 20
32 48
33 42
34 40
35 42
36 20
37 20
38 40
39 40
40 20
41 18
42 20
43 64
44 64
45 20
46 40
47 40
48 40
49 40
50 20
51 40
52 20
53 18
54 64
55 64
56 40
57 40
58 20
59 40
60 20
61 40
62 64
63 20
64 40
65 40
66 20
67 20
68 64
69 64
70 64

List of values

[1, 2, 4, 6, 4, 8, 8, 12, 12, 16, 20, 20, 18, 40, 40, 16, 18, 18, 16, 72, 40, 16, 40, 18, 96, 96, 18, 64, 20, 40, 20, 48, 42, 40, 42, 20, 20, 40, 40, 20, 18, 20, 64, 64, 20, 40, 40, 40, 40, 20, 40, 20, 18, 64, 64, 40, 40, 20, 40, 20, 40, 64, 20, 40, 40, 20, 20, 64, 64, 64]

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