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.

A241027 Smallest prime numbers p of length n having a decimal expansion x(1)x(2)... x(n) such that there exists an index j where x(j) = 1 and x(i) = 7 for i<>j, or 0 if no such prime exists.

Table of values

n a(n)
2 17
3 0
4 1777
5 71777
6 0
7 0
8 77777177
9 0
10 1777777777
11 71777777777
12 0
13 7177777777777
14 17777777777777
15 0
16 7717777777777777
17 0
18 0
19 7777177777777777777
20 71777777777777777777
21 0
22 7777717777777777777777
23 77717777777777777777777
24 0
25 7777771777777777777777777

List of values

[17, 0, 1777, 71777, 0, 0, 77777177, 0, 1777777777, 71777777777, 0, 7177777777777, 17777777777777, 0, 7717777777777777, 0, 0, 7777177777777777777, 71777777777777777777, 0, 7777717777777777777777, 77717777777777777777777, 0, 7777771777777777777777777]

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

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