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.

A067573 Numbers k > 1 such that sigma(phi(k))/sigma(k) > sigma(phi(j))/sigma(j) for all 1 < j < k.

Table of values

n a(n)
1 2
2 3
3 5
4 7
5 13
6 31
7 37
8 61
9 181
10 241
11 421
12 1009
13 1201
14 1321
15 1801
16 2161
17 2521
18 7561
19 12601
20 15121
21 30241
22 55441
23 110881
24 278263
25 332641
26 555911
27 666917
28 722473
29 1443853
30 2165407
31 3607403
32 4324321
33 7212581
34 8654539
35 10817761
36 21631147
37 36768847
38 43243201
39 61276871

List of values

[2, 3, 5, 7, 13, 31, 37, 61, 181, 241, 421, 1009, 1201, 1321, 1801, 2161, 2521, 7561, 12601, 15121, 30241, 55441, 110881, 278263, 332641, 555911, 666917, 722473, 1443853, 2165407, 3607403, 4324321, 7212581, 8654539, 10817761, 21631147, 36768847, 43243201, 61276871]

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

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