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.

A040174 Denominator of probability that 2 elements of S_n chosen at random (with replacement) generate S_n.

Table of values

n a(n)
1 1
2 4
3 2
4 8
5 40
6 120
7 168
8 6720
9 120960
10 44800
11 6652800
12 14515200
13 415134720

List of values

[1, 4, 2, 8, 40, 120, 168, 6720, 120960, 44800, 6652800, 14515200, 415134720]