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.

A057789 a(n) = Sum_{k = 1..n, gcd(k,n)=1} k*(n-k).

Table of values

n a(n)
1 0
2 1
3 4
4 6
5 20
6 10
7 56
8 44
9 84
10 60
11 220
12 92
13 364
14 182
15 280
16 344
17 816
18 318
19 1140
20 520
21 840
22 770
23 2024
24 760
25 2100
26 1300
27 2196
28 1540
29 4060
30 1240
31 4960
32 2736
33 3520
34 2992
35 4760
36 2580
37 8436
38 4218
39 5928
40 4240
41 11480
42 3612
43 13244
44 6380
45 8040
46 7590
47 17296
48 6128

List of values

[0, 1, 4, 6, 20, 10, 56, 44, 84, 60, 220, 92, 364, 182, 280, 344, 816, 318, 1140, 520, 840, 770, 2024, 760, 2100, 1300, 2196, 1540, 4060, 1240, 4960, 2736, 3520, 2992, 4760, 2580, 8436, 4218, 5928, 4240, 11480, 3612, 13244, 6380, 8040, 7590, 17296, 6128]