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.

A253824 Numbers m = concat(s,t) such that m = sigma(s) * sigma(t), where sigma(x) is the sum of the divisors of x.

Table of values

n a(n)
1 540
2 2352
3 28224
4 82890
5 737856
6 1524096
7 1531152
8 3429216
9 17062920
10 22264200
11 23268600
12 49447728
13 104941200
14 162496048
15 197499456
16 267450144
17 502334784
18 619672032
19 2347826040
20 2942021520
21 4045874976
22 4302305280
23 9876226752
24 22712348160
25 24705882348
26 33114541824
27 34144545792
28 45916416000

List of values

[540, 2352, 28224, 82890, 737856, 1524096, 1531152, 3429216, 17062920, 22264200, 23268600, 49447728, 104941200, 162496048, 197499456, 267450144, 502334784, 619672032, 2347826040, 2942021520, 4045874976, 4302305280, 9876226752, 22712348160, 24705882348, 33114541824, 34144545792, 45916416000]

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

Content is available under The OEIS End-User License Agreement.