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.

A087923 Number of ways of arranging the numbers 1 ... 2n into a 2 X n array so there is exactly one local maximum.

Table of values

n a(n)
1 2
2 16
3 208
4 3584
5 76544
6 1947648
7 57477120
8 1929117696
9 72545402880
10 3020819005440
11 137959904378880
12 6855868809216000
13 368270708268072960
14 21262037565623500800
15 1312956239068318924800
16 86347473137975269785600
17 6025205587810776514560000
18 444600907757468888806195200

List of values

[2, 16, 208, 3584, 76544, 1947648, 57477120, 1929117696, 72545402880, 3020819005440, 137959904378880, 6855868809216000, 368270708268072960, 21262037565623500800, 1312956239068318924800, 86347473137975269785600, 6025205587810776514560000, 444600907757468888806195200]

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

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