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.

A330725 a(0) = 0; thereafter a(n) = a(n-1) + sigma(n) if sigma(n) > a(n-1), otherwise a(n) = a(n-1) - sigma(n), where sigma is the sum of divisors function A000203.

Table of values

n a(n)
0 0
1 1
2 4
3 0
4 7
5 1
6 13
7 5
8 20
9 7
10 25
11 13
12 41
13 27
14 3
15 27
16 58
17 40
18 1
19 21
20 63
21 31
22 67
23 43
24 103
25 72
26 30
27 70
28 14
29 44
30 116
31 84
32 21
33 69
34 15
35 63
36 154
37 116
38 56
39 0
40 90
41 48
42 144
43 100
44 16
45 94
46 22
47 70
48 194
49 137
50 44
51 116
52 18
53 72
54 192
55 120
56 0
57 80
58 170
59 110
60 278
61 216
62 120
63 16

List of values

[0, 1, 4, 0, 7, 1, 13, 5, 20, 7, 25, 13, 41, 27, 3, 27, 58, 40, 1, 21, 63, 31, 67, 43, 103, 72, 30, 70, 14, 44, 116, 84, 21, 69, 15, 63, 154, 116, 56, 0, 90, 48, 144, 100, 16, 94, 22, 70, 194, 137, 44, 116, 18, 72, 192, 120, 0, 80, 170, 110, 278, 216, 120, 16]

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

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