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.

A050457 a(n) = Sum_{ d divides n, d==1 mod 4} d - Sum_{ d divides n, d==3 mod 4} d.

Table of values

n a(n)
1 1
2 1
3 -2
4 1
5 6
6 -2
7 -6
8 1
9 7
10 6
11 -10
12 -2
13 14
14 -6
15 -12
16 1
17 18
18 7
19 -18
20 6
21 12
22 -10
23 -22
24 -2
25 31
26 14
27 -20
28 -6
29 30
30 -12
31 -30
32 1
33 20
34 18
35 -36
36 7
37 38
38 -18
39 -28
40 6
41 42
42 12
43 -42
44 -10
45 42
46 -22
47 -46
48 -2
49 43
50 31
51 -36
52 14
53 54
54 -20
55 -60
56 -6
57 36
58 30
59 -58
60 -12
61 62
62 -30
63 -42
64 1
65 84
66 20
67 -66
68 18
69 44
70 -36
71 -70

List of values

[1, 1, -2, 1, 6, -2, -6, 1, 7, 6, -10, -2, 14, -6, -12, 1, 18, 7, -18, 6, 12, -10, -22, -2, 31, 14, -20, -6, 30, -12, -30, 1, 20, 18, -36, 7, 38, -18, -28, 6, 42, 12, -42, -10, 42, -22, -46, -2, 43, 31, -36, 14, 54, -20, -60, -6, 36, 30, -58, -12, 62, -30, -42, 1, 84, 20, -66, 18, 44, -36, -70]