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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.

A067886 Numbers k such that 2^k+1 and 2^k-1 have the same number of distinct prime factors.

Table of values

n a(n)
1 2
2 3
3 6
4 9
5 11
6 14
7 15
8 18
9 21
10 23
11 27
12 29
13 33
14 42
15 47
16 51
17 53
18 54
19 57
20 69
21 71
22 73
23 74
24 81
25 82
26 86
27 95
28 101
29 105
30 111
31 113
32 114
33 115
34 121
35 129
36 130
37 138
38 141
39 142
40 165
41 167
42 169
43 179
44 181
45 199
46 203
47 209
48 213
49 230
50 233
51 235
52 243
53 250
54 255
55 258
56 277
57 279
58 306
59 307

List of values

[2, 3, 6, 9, 11, 14, 15, 18, 21, 23, 27, 29, 33, 42, 47, 51, 53, 54, 57, 69, 71, 73, 74, 81, 82, 86, 95, 101, 105, 111, 113, 114, 115, 121, 129, 130, 138, 141, 142, 165, 167, 169, 179, 181, 199, 203, 209, 213, 230, 233, 235, 243, 250, 255, 258, 277, 279, 306, 307]

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

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