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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.

A299147 Numbers k such that sigma(k), sigma(k^2) and sigma(k^3) are primes.

Table of values

n a(n)
1 4
2 64
3 289
4 253541929
5 499477801
6 1260747049
7 14450203681
8 25391466409
9 256221229489
10 333456586849
11 341122579249
12 459926756041
13 911087431081
14 928731181849
15 1142288550841
16 2880002461249
17 2923070670601
18 3000305515321
19 4103999343889
20 4123226708329
21 4258977385441

List of values

[4, 64, 289, 253541929, 499477801, 1260747049, 14450203681, 25391466409, 256221229489, 333456586849, 341122579249, 459926756041, 911087431081, 928731181849, 1142288550841, 2880002461249, 2923070670601, 3000305515321, 4103999343889, 4123226708329, 4258977385441]

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

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