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.

A066973 a(n) = phi(binomial(2n, n)).

Table of values

n a(n)
1 1
2 2
3 8
4 24
5 72
6 240
7 960
8 2880
9 15360
10 69120
11 165888
12 912384
13 3041280
14 9123840
15 34062336
16 127733760
17 479001600
18 1596672000
19 6386688000
20 22992076800
21 102187008000
22 429185433600
23 1755758592000
24 6730407936000
25 28267713331200

List of values

[1, 2, 8, 24, 72, 240, 960, 2880, 15360, 69120, 165888, 912384, 3041280, 9123840, 34062336, 127733760, 479001600, 1596672000, 6386688000, 22992076800, 102187008000, 429185433600, 1755758592000, 6730407936000, 28267713331200]