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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.

A056190 a(n) = Sum_{d|n and gcd(d, n/d)=1} binomial(n,d).

Table of values

n a(n)
1 1
2 3
3 4
4 5
5 6
6 42
7 8
8 9
9 10
10 308
11 12
12 728
13 14
14 3538
15 3474
16 17
17 18
18 48792
19 20
20 20370
21 117632
22 705686
23 24
24 737520
25 26
26 10400952
27 28
28 1204544
29 30
30 185903342
31 32
32 33
33 193542210
34 2333606816
35 7049188
36 94202222
37 38
38 35345264542
39 8122434623

List of values

[1, 3, 4, 5, 6, 42, 8, 9, 10, 308, 12, 728, 14, 3538, 3474, 17, 18, 48792, 20, 20370, 117632, 705686, 24, 737520, 26, 10400952, 28, 1204544, 30, 185903342, 32, 33, 193542210, 2333606816, 7049188, 94202222, 38, 35345264542, 8122434623]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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