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.

A227759 Numbers n such that A227758(n) = sigma(sigma(n)) - sigma(n) - n < 0, where sigma(n) = A000203(n) = sum of the divisors of n.

Table of values

n a(n)
1 1
2 2
3 4
4 9
5 13
6 16
7 18
8 25
9 36
10 37
11 43
12 49
13 50
14 61
15 64
16 67
17 73
18 81
19 97
20 98
21 100
22 109
23 121
24 144
25 151
26 157
27 163
28 169
29 181
30 193
31 211
32 225
33 229
34 241
35 242
36 256
37 277
38 283
39 289
40 313
41 324
42 331
43 337
44 338
45 361
46 373
47 397
48 400
49 409
50 421
51 433
52 441
53 457
54 484
55 487
56 523
57 529

List of values

[1, 2, 4, 9, 13, 16, 18, 25, 36, 37, 43, 49, 50, 61, 64, 67, 73, 81, 97, 98, 100, 109, 121, 144, 151, 157, 163, 169, 181, 193, 211, 225, 229, 241, 242, 256, 277, 283, 289, 313, 324, 331, 337, 338, 361, 373, 397, 400, 409, 421, 433, 441, 457, 484, 487, 523, 529]

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

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