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.

A118689 Semiprimes for which the product of the digits is also a semiprime.

Table of values

n a(n)
1 4
2 6
3 9
4 14
5 22
6 25
7 33
8 35
9 55
10 57
11 77
12 91
13 119
14 122
15 123
16 133
17 141
18 155
19 161
20 177
21 213
22 215
23 217
24 221
25 321
26 371
27 411
28 515
29 517
30 551
31 611
32 713
33 717
34 721
35 731
36 771
37 1114
38 1119
39 1133
40 1135
41 1137
42 1141
43 1157
44 1177
45 1191
46 1271
47 1313
48 1315
49 1317
50 1351
51 1371
52 1411

List of values

[4, 6, 9, 14, 22, 25, 33, 35, 55, 57, 77, 91, 119, 122, 123, 133, 141, 155, 161, 177, 213, 215, 217, 221, 321, 371, 411, 515, 517, 551, 611, 713, 717, 721, 731, 771, 1114, 1119, 1133, 1135, 1137, 1141, 1157, 1177, 1191, 1271, 1313, 1315, 1317, 1351, 1371, 1411]

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

Content is available under The OEIS End-User License Agreement.