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.

A172095 Integers k such that k-1,k,k+1 have few distinct primes: k=p^r, p odd prime, and (k^2-1)/8 divisible by at most two distinct prime factors.

Table of values

n a(n)
1 3
2 5
3 7
4 9
5 11
6 13
7 17
8 19
9 27
10 37
11 53
12 107
13 163
14 243
15 2187
16 2917
17 4373
18 8747
19 1594323
20 86093443

List of values

[3, 5, 7, 9, 11, 13, 17, 19, 27, 37, 53, 107, 163, 243, 2187, 2917, 4373, 8747, 1594323, 86093443]