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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.

A304201 a(n) is the number of cyclic permutations of length n that admit a [1,-1,-1]-gridding.

Table of values

n a(n)
0 1
1 1
2 1
3 2
4 5
5 15
6 43
7 120
8 338
9 952
10 2672
11 7494
12 21035
13 59115
14 166433
15 469560
16 1327802
17 3763545
18 10692500
19 30447858
20 86894361
21 248506757
22 712109663
23 2044402512
24 5879579540
25 16937048040
26 48864612668
27 141179970820
28 408444645375
29 1183143522435
30 3431241484223
31 9961919944284

List of values

[1, 1, 1, 2, 5, 15, 43, 120, 338, 952, 2672, 7494, 21035, 59115, 166433, 469560, 1327802, 3763545, 10692500, 30447858, 86894361, 248506757, 712109663, 2044402512, 5879579540, 16937048040, 48864612668, 141179970820, 408444645375, 1183143522435, 3431241484223, 9961919944284]

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

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