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.

A244439 Numbers n such that phi(n)*sigma(n) = phi(n+1)*sigma(n+1).

Table of values

n a(n)
1 5
2 55
3 56
4 123
5 135
6 147
7 175
8 304
9 351
10 644
11 1015
12 2464
13 19304
14 61131
15 162524
16 476671
17 567644
18 712724
19 801944
20 2435488
21 3346399
22 3885056
23 4555999
24 8085560
25 8369360
26 12516692
27 22702119
28 29628800
29 83884031
30 83994624
31 84789247
32 354812535
33 860616295
34 1091535704

List of values

[5, 55, 56, 123, 135, 147, 175, 304, 351, 644, 1015, 2464, 19304, 61131, 162524, 476671, 567644, 712724, 801944, 2435488, 3346399, 3885056, 4555999, 8085560, 8369360, 12516692, 22702119, 29628800, 83884031, 83994624, 84789247, 354812535, 860616295, 1091535704]

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

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