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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.

A343553 a(n) = Sum_{1 <= x_1 <= x_2 <= ... <= x_n = n} gcd(x_1, x_2, ... , x_n).

Table of values

n a(n)
1 1
2 3
3 8
4 26
5 74
6 287
7 930
8 3572
9 12966
10 49379
11 184766
12 710712
13 2704168
14 10427822
15 40123208
16 155289768
17 601080406
18 2334740919
19 9075135318
20 35352194658
21 137846990678
22 538302226835
23 2104098963742
24 8233721100024
25 32247603765020
26 126412458921072
27 495918569262798

List of values

[1, 3, 8, 26, 74, 287, 930, 3572, 12966, 49379, 184766, 710712, 2704168, 10427822, 40123208, 155289768, 601080406, 2334740919, 9075135318, 35352194658, 137846990678, 538302226835, 2104098963742, 8233721100024, 32247603765020, 126412458921072, 495918569262798]

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

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