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.

A348660 a(n) = Sum_{d|n, d <= sqrt(n)} (-1)^(n/d + 1) * d.

Table of values

n a(n)
1 1
2 -1
3 1
4 -3
5 1
6 1
7 1
8 -3
9 4
10 1
11 1
12 -6
13 1
14 1
15 4
16 -7
17 1
18 -2
19 1
20 1
21 4
22 1
23 1
24 -10
25 6
26 1
27 4
28 1
29 1
30 -7
31 1
32 -7
33 4
34 1
35 6
36 -8
37 1
38 1
39 4
40 -12
41 1
42 4
43 1
44 1
45 9
46 1
47 1
48 -16
49 8
50 -4
51 4
52 1
53 1
54 4
55 6
56 -14
57 4
58 1
59 1
60 -13
61 1
62 1
63 11
64 -15
65 6
66 4
67 1
68 1
69 4
70 -11
71 1
72 -8
73 1
74 1
75 9
76 1
77 8
78 4
79 1
80 -20

List of values

[1, -1, 1, -3, 1, 1, 1, -3, 4, 1, 1, -6, 1, 1, 4, -7, 1, -2, 1, 1, 4, 1, 1, -10, 6, 1, 4, 1, 1, -7, 1, -7, 4, 1, 6, -8, 1, 1, 4, -12, 1, 4, 1, 1, 9, 1, 1, -16, 8, -4, 4, 1, 1, 4, 6, -14, 4, 1, 1, -13, 1, 1, 11, -15, 6, 4, 1, 1, 4, -11, 1, -8, 1, 1, 9, 1, 8, 4, 1, -20]