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.

A056687 Numbers k such that 50*R_k + 9 is prime, where R_k = 11...1 is the repunit (A002275) of length k.

Table of values

n a(n)
1 1
2 7
3 11
4 17
5 25
6 31
7 137
8 187
9 221
10 337
11 1001
12 2743
13 6529
14 38689
15 39463

List of values

[1, 7, 11, 17, 25, 31, 137, 187, 221, 337, 1001, 2743, 6529, 38689, 39463]