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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.

A350900 Triangle read by rows: T(n, k) = Sum_{i=1..n} gcd(i,n) / gcd(gcd(i,k),n) for 1 <= k <= n.

Table of values

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

List of values

[1, 3, 2, 5, 5, 3, 8, 5, 8, 4, 9, 9, 9, 9, 5, 15, 10, 9, 10, 15, 6, 13, 13, 13, 13, 13, 13, 7, 20, 12, 20, 9, 20, 12, 20, 8, 21, 21, 11, 21, 21, 11, 21, 21, 9, 27, 18, 27, 18, 15, 18, 27, 18, 27, 10, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 11, 40, 25, 24, 20, 40, 15, 40, 20, 24, 25, 40, 12]

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