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.

A100349 Numbers n such that n-2^k is a prime or semiprime for all k > 0 with 2^k < n.

Table of values

n a(n)
1 4
2 6
3 7
4 8
5 11
6 13
7 15
8 19
9 21
10 23
11 25
12 27
13 37
14 39
15 41
16 45
17 51
18 55
19 57
20 63
21 69
22 73
23 75
24 81
25 87
26 93
27 99
28 105
29 111
30 117
31 123
32 135
33 147
34 153
35 159
36 165
37 171
38 195
39 201
40 213
41 219
42 225
43 231
44 237
45 243
46 255
47 267
48 273
49 285
50 297
51 315
52 321
53 363
54 369
55 399
56 405
57 411
58 423
59 435
60 447

List of values

[4, 6, 7, 8, 11, 13, 15, 19, 21, 23, 25, 27, 37, 39, 41, 45, 51, 55, 57, 63, 69, 73, 75, 81, 87, 93, 99, 105, 111, 117, 123, 135, 147, 153, 159, 165, 171, 195, 201, 213, 219, 225, 231, 237, 243, 255, 267, 273, 285, 297, 315, 321, 363, 369, 399, 405, 411, 423, 435, 447]

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

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