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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.

A264544 Number of (n+1) X (2+1) arrays of permutations of 0..n*3+2 with each element having directed index change -1,1 -1,2 1,0 or 0,-1.

Table of values

n a(n)
1 1
2 2
3 5
4 10
5 21
6 44
7 93
8 196
9 413
10 870
11 1833
12 3862
13 8137
14 17144
15 36121
16 76104
17 160345
18 337834
19 711789
20 1499682
21 3159709
22 6657252
23 14026293
24 29552268
25 62264245
26 131185742
27 276397777
28 582347822
29 1226959889
30 2585105520
31 5446608817

List of values

[1, 2, 5, 10, 21, 44, 93, 196, 413, 870, 1833, 3862, 8137, 17144, 36121, 76104, 160345, 337834, 711789, 1499682, 3159709, 6657252, 14026293, 29552268, 62264245, 131185742, 276397777, 582347822, 1226959889, 2585105520, 5446608817]

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

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