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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.

A104527 Denominator of sum(1/(phi(k)sigma(k)),k=1..n), where phi(k) is the totient function and sigma(k) is the sum of the divisors function.

Table of values

n a(n)
1 1
2 3
3 24
4 168
5 7
6 168
7 112
8 1680
9 21840
10 65520
11 65520
12 16380
13 32760
14 21840
15 29120
16 902720
17 8124480
18 8124480
19 1624896
20 1624896
21 3249792
22 5416320
23 59579520
24 59579520
25 59579520
26 178738560
27 178738560
28 178738560
29 178738560
30 178738560

List of values

[1, 3, 24, 168, 7, 168, 112, 1680, 21840, 65520, 65520, 16380, 32760, 21840, 29120, 902720, 8124480, 8124480, 1624896, 1624896, 3249792, 5416320, 59579520, 59579520, 59579520, 178738560, 178738560, 178738560, 178738560, 178738560]

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

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