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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.

A319132 a(n) = Sum_{d|n} Sum_{j|d} mu(j)^2*j, where mu = Möbius function (A008683).

Table of values

n a(n)
1 1
2 4
3 5
4 7
5 7
6 20
7 9
8 10
9 9
10 28
11 13
12 35
13 15
14 36
15 35
16 13
17 19
18 36
19 21
20 49
21 45
22 52
23 25
24 50
25 13
26 60
27 13
28 63
29 31
30 140
31 33
32 16
33 65
34 76
35 63
36 63
37 39
38 84
39 75
40 70
41 43
42 180
43 45
44 91
45 63
46 100
47 49
48 65
49 17
50 52
51 95
52 105
53 55
54 52
55 91
56 90
57 105
58 124
59 61
60 245
61 63
62 132
63 81
64 19
65 105
66 260
67 69
68 133
69 125
70 252

List of values

[1, 4, 5, 7, 7, 20, 9, 10, 9, 28, 13, 35, 15, 36, 35, 13, 19, 36, 21, 49, 45, 52, 25, 50, 13, 60, 13, 63, 31, 140, 33, 16, 65, 76, 63, 63, 39, 84, 75, 70, 43, 180, 45, 91, 63, 100, 49, 65, 17, 52, 95, 105, 55, 52, 91, 90, 105, 124, 61, 245, 63, 132, 81, 19, 105, 260, 69, 133, 125, 252]

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

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