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.

A247699 Smallest prime such that, in binary, prefixing and suffixing n-bit numbers, the latter permitted to include leading 0's, does not produce a prime.

Table of values

n a(n)
1 3
2 5
3 523
4 47543
5 1951071427

List of values

[3, 5, 523, 47543, 1951071427]