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.

A232444 Numbers n such that sigma(n) and sigma(n^2) are primes.

Table of values

n a(n)
1 2
2 4
3 64
4 289
5 729
6 15625
7 7091569
8 7778521
9 11607649
10 15912121
11 43546801
12 56957209
13 138980521
14 143688169
15 171845881
16 210801361
17 211673401
18 253541929
19 256224049
20 275792449
21 308810329
22 329386201
23 357172201
24 408807961
25 499477801
26 531625249
27 769341169
28 1073741824
29 1260747049

List of values

[2, 4, 64, 289, 729, 15625, 7091569, 7778521, 11607649, 15912121, 43546801, 56957209, 138980521, 143688169, 171845881, 210801361, 211673401, 253541929, 256224049, 275792449, 308810329, 329386201, 357172201, 408807961, 499477801, 531625249, 769341169, 1073741824, 1260747049]