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.

A325637 Numbers k for which gcd(2k, sigma(k)) = 2k.

Table of values

n a(n)
1 6
2 28
3 496
4 8128
5 30240
6 32760
7 2178540
8 23569920
9 33550336
10 45532800
11 142990848
12 1379454720
13 8589869056
14 43861478400
15 66433720320
16 137438691328
17 153003540480
18 403031236608
19 704575228896
20 181742883469056
21 6088728021160320
22 14942123276641920
23 20158185857531904
24 275502900594021408
25 622286506811515392
26 2305843008139952128

List of values

[6, 28, 496, 8128, 30240, 32760, 2178540, 23569920, 33550336, 45532800, 142990848, 1379454720, 8589869056, 43861478400, 66433720320, 137438691328, 153003540480, 403031236608, 704575228896, 181742883469056, 6088728021160320, 14942123276641920, 20158185857531904, 275502900594021408, 622286506811515392, 2305843008139952128]

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

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