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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.

A227240 Numbers k such that sigma(k) divides sigma(2*k) and sigma(2*k + 1).

Table of values

n a(n)
1 1
2 3
3 5
4 7
5 11
6 23
7 29
8 41
9 53
10 77
11 83
12 89
13 103
14 113
15 131
16 143
17 173
18 179
19 191
20 233
21 239
22 251
23 281
24 293
25 359
26 419
27 431
28 443
29 491
30 509
31 533
32 593
33 641
34 653
35 659
36 667
37 683
38 719
39 743
40 761
41 807
42 809
43 817
44 911
45 953
46 1013
47 1019
48 1031
49 1049
50 1073
51 1103
52 1223
53 1229
54 1289
55 1409

List of values

[1, 3, 5, 7, 11, 23, 29, 41, 53, 77, 83, 89, 103, 113, 131, 143, 173, 179, 191, 233, 239, 251, 281, 293, 359, 419, 431, 443, 491, 509, 533, 593, 641, 653, 659, 667, 683, 719, 743, 761, 807, 809, 817, 911, 953, 1013, 1019, 1031, 1049, 1073, 1103, 1223, 1229, 1289, 1409]

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

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