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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.

A015759 Numbers k such that phi(k) | sigma_2(k).

Table of values

n a(n)
1 1
2 2
3 3
4 6
5 22
6 33
7 66
8 750
9 27798250
10 41697375
11 76745867
12 83394750
13 153491734
14 207656250
15 230237601
16 460475202
17 917342250
18 969062500
19 2907187500
20 4528006153
21 5952812500
22 9056012306
23 13584018459
24 17858437500
25 27168036918
26 31979062500
27 57559400250

List of values

[1, 2, 3, 6, 22, 33, 66, 750, 27798250, 41697375, 76745867, 83394750, 153491734, 207656250, 230237601, 460475202, 917342250, 969062500, 2907187500, 4528006153, 5952812500, 9056012306, 13584018459, 17858437500, 27168036918, 31979062500, 57559400250]

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

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