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.

A180090 Sigma-powerful numbers: powerful numbers n such that sigma(n) is also powerful. An incomplete version of A337045.

Table of values

n a(n)
1 81
2 343
3 400
4 1705636
5 3648100
6 13645088
7 25992000
8 26680500
9 29184800
10 80802000
11 110215125
12 178054848
13 180093375
14 213444000
15 310144500
16 408632609
17 575664500
18 1055340196
19 1120504500
20 1476326929
21 1667329664
22 2066544500

List of values

[81, 343, 400, 1705636, 3648100, 13645088, 25992000, 26680500, 29184800, 80802000, 110215125, 178054848, 180093375, 213444000, 310144500, 408632609, 575664500, 1055340196, 1120504500, 1476326929, 1667329664, 2066544500]