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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.

A081398 Numbers k for which the number of common prime factors of sigma(k) and phi(k) is exactly six (ignoring multiplicity).

Table of values

n a(n)
1 2003639
2 2179316
3 2180057
4 2382974
5 2689561
6 2720567
7 2761873
8 2933675
9 3145572
10 3435381
11 3925463
12 4007278
13 4137111
14 4212692
15 4360114
16 4947971
17 5172881
18 5379122
19 5441134
20 5458673
21 5523746
22 5675816
23 5748831
24 5867350
25 5957435
26 6010917
27 6537948
28 6540171
29 6561511

List of values

[2003639, 2179316, 2180057, 2382974, 2689561, 2720567, 2761873, 2933675, 3145572, 3435381, 3925463, 4007278, 4137111, 4212692, 4360114, 4947971, 5172881, 5379122, 5441134, 5458673, 5523746, 5675816, 5748831, 5867350, 5957435, 6010917, 6537948, 6540171, 6561511]

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

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