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.

A333557 a(n) = Sum_{d|n, gcd(d, n/d) = 1} uphi(d) * uphi(n/d), where uphi = unitary totient function (A047994).

Table of values

n a(n)
1 1
2 2
3 4
4 6
5 8
6 8
7 12
8 14
9 16
10 16
11 20
12 24
13 24
14 24
15 32
16 30
17 32
18 32
19 36
20 48
21 48
22 40
23 44
24 56
25 48
26 48
27 52
28 72
29 56
30 64
31 60
32 62
33 80
34 64
35 96
36 96
37 72
38 72
39 96
40 112
41 80
42 96
43 84
44 120
45 128
46 88
47 92
48 120
49 96
50 96
51 128
52 144
53 104
54 104
55 160
56 168
57 144
58 112
59 116
60 192
61 120
62 120
63 192
64 126
65 192
66 160
67 132
68 192
69 176
70 192

List of values

[1, 2, 4, 6, 8, 8, 12, 14, 16, 16, 20, 24, 24, 24, 32, 30, 32, 32, 36, 48, 48, 40, 44, 56, 48, 48, 52, 72, 56, 64, 60, 62, 80, 64, 96, 96, 72, 72, 96, 112, 80, 96, 84, 120, 128, 88, 92, 120, 96, 96, 128, 144, 104, 104, 160, 168, 144, 112, 116, 192, 120, 120, 192, 126, 192, 160, 132, 192, 176, 192]