cp's OEIS Frontend

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.

A343517 a(n) = Sum_{1 <= x_1 <= x_2 <= ... <= x_n <= n} gcd(x_1, x_2, ... , x_n, n).

Table of values

n a(n)
1 1
2 4
3 12
4 42
5 130
6 506
7 1722
8 6622
9 24426
10 93427
11 352726
12 1359388
13 5200312
14 20097156
15 77567064
16 300787366
17 1166803126
18 4539197723
19 17672631918
20 68933307843
21 269129530770
22 1052113994340
23 4116715363822
24 16124224571368
25 63205303313900
26 247961973949536

List of values

[1, 4, 12, 42, 130, 506, 1722, 6622, 24426, 93427, 352726, 1359388, 5200312, 20097156, 77567064, 300787366, 1166803126, 4539197723, 17672631918, 68933307843, 269129530770, 1052113994340, 4116715363822, 16124224571368, 63205303313900, 247961973949536]

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

Content is available under The OEIS End-User License Agreement.