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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.

A129843 a(n) = number of positive integers that are <= n and are coprime to n!! (n!! = A006882(n)).

Table of values

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

List of values

[1, 1, 2, 2, 3, 2, 3, 3, 4, 2, 4, 3, 4, 3, 4, 3, 5, 4, 5, 5, 5, 4, 5, 5, 5, 4, 5, 4, 5, 5, 5, 6, 6, 5, 6, 5, 6, 5, 6, 5, 6, 6, 6, 7, 6, 6, 6, 7, 6, 7, 6, 7, 6, 8, 6, 8, 6, 7, 6, 8, 6, 8, 6, 8, 7, 8, 7, 9, 7, 9, 7, 10, 7, 10, 7, 10, 7, 10, 7, 11]

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