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.

A263420 Number of n X 2 arrays of permutations of 0..n*2-1 with each element moved a city block distance of 0 or 2.

Table of values

n a(n)
1 1
2 4
3 36
4 196
5 961
6 5329
7 29584
8 160000
9 868624
10 4739329
11 25816561
12 140517316
13 765186244
14 4167218916
15 22692108321
16 123567013441
17 672885527616
18 3664192267264
19 19953231345216
20 108654793385121
21 591677262389889

List of values

[1, 4, 36, 196, 961, 5329, 29584, 160000, 868624, 4739329, 25816561, 140517316, 765186244, 4167218916, 22692108321, 123567013441, 672885527616, 3664192267264, 19953231345216, 108654793385121, 591677262389889]

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

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