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.

A280587 Composite numbers k such that phi(x) = phi(k) has only 2 solutions: x = k and x = 2*k.

Table of values

n a(n)
1 81
2 121
3 343
4 361
5 529
6 649
7 841
8 961
9 1219
10 1331
11 1537
12 1633
13 1837
14 1849
15 1909
16 1969
17 2047
18 2209
19 2401
20 2497
21 2773
22 2809
23 2959
24 3113
25 3127
26 3151
27 3223
28 3421
29 3481
30 3487
31 3841
32 3901
33 3953
34 4189
35 4321
36 4399
37 4531
38 4661
39 4741
40 4829
41 4897
42 4913
43 5041
44 5129
45 5137
46 5191
47 5269
48 5401
49 5539
50 5753

List of values

[81, 121, 343, 361, 529, 649, 841, 961, 1219, 1331, 1537, 1633, 1837, 1849, 1909, 1969, 2047, 2209, 2401, 2497, 2773, 2809, 2959, 3113, 3127, 3151, 3223, 3421, 3481, 3487, 3841, 3901, 3953, 4189, 4321, 4399, 4531, 4661, 4741, 4829, 4897, 4913, 5041, 5129, 5137, 5191, 5269, 5401, 5539, 5753]

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

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