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.

A241021 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) = 9 for i<>j, or 0 if no such prime exists.

Table of values

n a(n)
2 19
3 199
4 1999
5 99991
6 199999
7 9999991
8 19999999
9 0
10 9199999999
11 99999199999
12 991999999999
13 9919999999999
14 99999999991999
15 919999999999999
16 9999999999999199
17 99919999999999999
18 0
19 9991999999999999999
20 99999199999999999999
21 0
22 9991999999999999999999

List of values

[19, 199, 1999, 99991, 199999, 9999991, 19999999, 0, 9199999999, 99999199999, 991999999999, 9919999999999, 99999999991999, 919999999999999, 9999999999999199, 99919999999999999, 0, 9991999999999999999, 99999199999999999999, 0, 9991999999999999999999]

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

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