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.

A006580 a(n) = Sum_{k=1..n-1} lcm(k,n-k).

Table of values

n a(n)
0 0
1 0
2 1
3 4
4 8
5 20
6 21
7 56
8 60
9 96
10 105
11 220
12 152
13 364
14 301
15 360
16 464
17 816
18 549
19 1140
20 760
21 1036
22 1221
23 2024
24 1196
25 2200
26 2041
27 2484
28 2184
29 4060
30 2205
31 4960
32 3664
33 4224
34 4641
35 5180
36 4008
37 8436
38 6517
39 7072
40 5980
41 11480
42 6321
43 13244
44 8888
45 9540
46 11661
47 17296

List of values

[0, 0, 1, 4, 8, 20, 21, 56, 60, 96, 105, 220, 152, 364, 301, 360, 464, 816, 549, 1140, 760, 1036, 1221, 2024, 1196, 2200, 2041, 2484, 2184, 4060, 2205, 4960, 3664, 4224, 4641, 5180, 4008, 8436, 6517, 7072, 5980, 11480, 6321, 13244, 8888, 9540, 11661, 17296]