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.

A247483 a(1)=4; for n>=1, a(n+1) is the smallest palindromic semiprime with a(n) as a central substring.

Table of values

n a(n)
1 4
2 141
3 41414
4 1414141
5 314141413
6 33141414133
7 3331414141333
8 14333141414133341
9 121433314141413334121
10 1012143331414141333412101
11 17101214333141414133341210171
12 3171012143331414141333412101713
13 19317101214333141414133341210171391

List of values

[4, 141, 41414, 1414141, 314141413, 33141414133, 3331414141333, 14333141414133341, 121433314141413334121, 1012143331414141333412101, 17101214333141414133341210171, 3171012143331414141333412101713, 19317101214333141414133341210171391]

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

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