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.

A332261 Numbers that yield a prime whenever a '4' is inserted between any two digits.

Table of values

n a(n)
1 0
2 1
3 2
4 3
5 4
6 5
7 6
8 7
9 8
10 9
11 19
12 21
13 37
14 39
15 43
16 49
17 51
18 57
19 61
20 63
21 67
22 73
23 91
24 97
25 109
26 129
27 147
28 153
29 159
30 171
31 187
32 199
33 211
34 223
35 237
36 241
37 247
38 259
39 267
40 333
41 349
42 357
43 363
44 409
45 421
46 423
47 441
48 447
49 457
50 463
51 493
52 517
53 537
54 541
55 543
56 549
57 571
58 579
59 583
60 627
61 649
62 681

List of values

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 21, 37, 39, 43, 49, 51, 57, 61, 63, 67, 73, 91, 97, 109, 129, 147, 153, 159, 171, 187, 199, 211, 223, 237, 241, 247, 259, 267, 333, 349, 357, 363, 409, 421, 423, 441, 447, 457, 463, 493, 517, 537, 541, 543, 549, 571, 579, 583, 627, 649, 681]

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

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