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.

A256527 a(n) is the least number k > 0 such that sigma(k) = phi(n*k).

Table of values

n a(n)
1 1
2 1
3 15
4 3
5 14
6 6
7 6
8 42
9 30
10 42
11 168
12 210
13 210
14 420
15 840
16 20790
17 20790
18 9240
19 9240
20 83160
21 120120
22 3984120
23 5165160
24 43825320
25 26860680
26 43825320
27 1304863560
28 569729160
29 569729160
30 16522145640
31 18176198040
32 563462139240
33 1140028049160
34 3844800479520
35 1255683068640
36 65361608151840
37 65361608151840
38 65361608151840
39 413956851628320
40 1241870554884960
41 1241870554884960

List of values

[1, 1, 15, 3, 14, 6, 6, 42, 30, 42, 168, 210, 210, 420, 840, 20790, 20790, 9240, 9240, 83160, 120120, 3984120, 5165160, 43825320, 26860680, 43825320, 1304863560, 569729160, 569729160, 16522145640, 18176198040, 563462139240, 1140028049160, 3844800479520, 1255683068640, 65361608151840, 65361608151840, 65361608151840, 413956851628320, 1241870554884960, 1241870554884960]

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

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