cp's OEIS Frontend

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.

A308150 Numbers k such that sigma(k) mod k is prime, where sigma = A000203.

Table of values

n a(n)
1 4
2 8
3 18
4 20
5 21
6 27
7 32
8 35
9 36
10 39
11 50
12 55
13 57
14 63
15 65
16 77
17 85
18 98
19 100
20 104
21 111
22 115
23 125
24 128
25 129
26 155
27 161
28 171
29 175
30 185
31 187
32 189
33 196
34 201
35 203
36 205
37 209
38 221
39 235
40 237
41 242
42 245
43 265
44 275
45 279
46 291
47 299
48 305
49 309
50 319
51 323
52 324
53 325
54 327
55 335
56 338
57 341
58 365
59 371
60 377
61 381
62 385
63 391

List of values

[4, 8, 18, 20, 21, 27, 32, 35, 36, 39, 50, 55, 57, 63, 65, 77, 85, 98, 100, 104, 111, 115, 125, 128, 129, 155, 161, 171, 175, 185, 187, 189, 196, 201, 203, 205, 209, 221, 235, 237, 242, 245, 265, 275, 279, 291, 299, 305, 309, 319, 323, 324, 325, 327, 335, 338, 341, 365, 371, 377, 381, 385, 391]

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

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