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.

A100521 Denominator of Sum_{k=0..2*n} (-1)^k/binomial(2*n, k)^2.

Table of values

n a(n)
0 1
1 4
2 72
3 1200
4 19600
5 635040
6 25613280
7 82450368
8 9275666400
9 595703908800
10 2048086772160
11 23459903026560
12 413676290035008
13 4419618483280000
14 3221901874311120000
15 361282596839420256000
16 2630246784565779288000
17 9628029406360113091200
18 1310481780310126504080000

List of values

[1, 4, 72, 1200, 19600, 635040, 25613280, 82450368, 9275666400, 595703908800, 2048086772160, 23459903026560, 413676290035008, 4419618483280000, 3221901874311120000, 361282596839420256000, 2630246784565779288000, 9628029406360113091200, 1310481780310126504080000]

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

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