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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.

A067260 Numbers k such that sigma(k+1) = 2*phi(k).

Table of values

n a(n)
1 13
2 43
3 109
4 151
5 589
6 883
7 2143
8 2725
9 4825
10 4921
11 9541
12 13189
13 21637
14 22249
15 22489
16 29971
17 30229
18 33787
19 36247
20 72541
21 73513
22 83287
23 94489
24 109213
25 113269
26 117367
27 189103
28 190489
29 198457
30 216529
31 247597
32 277447
33 297307
34 320137
35 353821
36 357751
37 376753
38 391543

List of values

[13, 43, 109, 151, 589, 883, 2143, 2725, 4825, 4921, 9541, 13189, 21637, 22249, 22489, 29971, 30229, 33787, 36247, 72541, 73513, 83287, 94489, 109213, 113269, 117367, 189103, 190489, 198457, 216529, 247597, 277447, 297307, 320137, 353821, 357751, 376753, 391543]

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

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