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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.

A123998 Numbers k such that 2k+1 and 4k+1 are primes.

Table of values

n a(n)
1 1
2 3
3 9
4 15
5 18
6 39
7 48
8 69
9 78
10 99
11 105
12 114
13 135
14 153
15 165
16 168
17 183
18 189
19 219
20 249
21 273
22 288
23 300
24 303
25 309
26 330
27 345
28 363
29 405
30 414
31 438
32 468
33 483
34 498
35 504
36 534
37 585
38 618
39 639
40 648
41 699
42 714
43 729
44 765
45 804
46 813
47 828
48 879
49 933
50 1005
51 1014
52 1044
53 1065
54 1068

List of values

[1, 3, 9, 15, 18, 39, 48, 69, 78, 99, 105, 114, 135, 153, 165, 168, 183, 189, 219, 249, 273, 288, 300, 303, 309, 330, 345, 363, 405, 414, 438, 468, 483, 498, 504, 534, 585, 618, 639, 648, 699, 714, 729, 765, 804, 813, 828, 879, 933, 1005, 1014, 1044, 1065, 1068]

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

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