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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.

A362624 a(n) = Sum_{d|n, gcd(d,n/d)=1} psi(d), where psi is the Dedekind psi function (A001615).

Table of values

n a(n)
1 1
2 4
3 5
4 7
5 7
6 20
7 9
8 13
9 13
10 28
11 13
12 35
13 15
14 36
15 35
16 25
17 19
18 52
19 21
20 49
21 45
22 52
23 25
24 65
25 31
26 60
27 37
28 63
29 31
30 140
31 33
32 49
33 65
34 76
35 63
36 91
37 39
38 84
39 75
40 91
41 43
42 180
43 45
44 91
45 91
46 100
47 49
48 125
49 57
50 124
51 95
52 105
53 55
54 148
55 91
56 117
57 105
58 124
59 61
60 245
61 63
62 132
63 117
64 97
65 105
66 260
67 69
68 133

List of values

[1, 4, 5, 7, 7, 20, 9, 13, 13, 28, 13, 35, 15, 36, 35, 25, 19, 52, 21, 49, 45, 52, 25, 65, 31, 60, 37, 63, 31, 140, 33, 49, 65, 76, 63, 91, 39, 84, 75, 91, 43, 180, 45, 91, 91, 100, 49, 125, 57, 124, 95, 105, 55, 148, 91, 117, 105, 124, 61, 245, 63, 132, 117, 97, 105, 260, 69, 133]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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