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.

A103054 Numbers k such that 7*10^k + 2*R_k + 7 is prime, where R_k = 11...1 is the repunit (A002275) of length k.

Table of values

n a(n)
1 1
2 3
3 4
4 7
5 9
6 13
7 33
8 37
9 76
10 147
11 297
12 1851
13 3457
14 3609
15 45219

List of values

[1, 3, 4, 7, 9, 13, 33, 37, 76, 147, 297, 1851, 3457, 3609, 45219]