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.

A015721 Composite and even n such that phi(n) * sigma(n) is one less than a square.

Table of values

n a(n)
1 6
2 22
3 44
4 76
5 82
6 140
7 190
8 354
9 392
10 650
11 944
12 1072
13 1142
14 1150
15 1668
16 2276
17 4176
18 4192
19 4262
20 5090
21 7260
22 8660
23 15026
24 16064
25 22926
26 29746
27 39436
28 42872
29 74666
30 87498
31 94786
32 101882
33 115772
34 118928
35 127580
36 151348

List of values

[6, 22, 44, 76, 82, 140, 190, 354, 392, 650, 944, 1072, 1142, 1150, 1668, 2276, 4176, 4192, 4262, 5090, 7260, 8660, 15026, 16064, 22926, 29746, 39436, 42872, 74666, 87498, 94786, 101882, 115772, 118928, 127580, 151348]

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

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