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.

A217265 Numbers with 4 or more prime factors (with multiplicity) such that every concatenation of their prime factors is prime.

Table of values

n a(n)
1 21249
2 33271
3 89937
4 146461
5 147833
6 148519
7 164297
8 175257
9 211631
10 216953
11 234269
12 254849
13 261023
14 269941
15 311229
16 318033
17 348823
18 377001
19 390447
20 520209
21 561491
22 848239
23 941679
24 943679
25 957447
26 960957
27 1012879
28 1110159
29 1221431
30 1410399
31 1525203
32 1681729

List of values

[21249, 33271, 89937, 146461, 147833, 148519, 164297, 175257, 211631, 216953, 234269, 254849, 261023, 269941, 311229, 318033, 348823, 377001, 390447, 520209, 561491, 848239, 941679, 943679, 957447, 960957, 1012879, 1110159, 1221431, 1410399, 1525203, 1681729]

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

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