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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.

A066881 Numbers n such that sigma(phi(n))/sigma(n) is an integer >= 4.

Table of values

n a(n)
1 121679
2 1043909
3 2350171
4 2918263
5 3396103
6 3566807
7 3688067
8 4019467
9 4562827
10 5963407
11 7300697
12 7485979
13 7853933
14 8103301
15 8364151
16 9237779
17 9514213
18 9638527
19 10531123
20 11094619
21 11384447
22 12721937
23 13576267
24 15331313

List of values

[121679, 1043909, 2350171, 2918263, 3396103, 3566807, 3688067, 4019467, 4562827, 5963407, 7300697, 7485979, 7853933, 8103301, 8364151, 9237779, 9514213, 9638527, 10531123, 11094619, 11384447, 12721937, 13576267, 15331313]

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

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