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.

A276238 Numbers k such that 2^sigma(k) == -1 (mod k).

Table of values

n a(n)
1 1
2 5
3 4097
4 7361
5 85073
6 658529
7 3999137
8 16777217
9 50281793
10 68544541
11 72281281
12 78202273
13 102931841
14 128459137
15 204786497
16 244622261
17 336392993
18 613750913
19 714155969
20 785432401
21 1008179297

List of values

[1, 5, 4097, 7361, 85073, 658529, 3999137, 16777217, 50281793, 68544541, 72281281, 78202273, 102931841, 128459137, 204786497, 244622261, 336392993, 613750913, 714155969, 785432401, 1008179297]

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

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