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.

A227399 Number of permutations i_1, ..., i_n of 1, ..., n with i_1 = 1 and i_n = n such that i_1+2*i_2, i_2+2*i_3, ..., i_{n-1}+2*i_n, i_n+2*i_1 are pairwise distinct modulo n.

Table of values

n a(n)
1 1
2 1
3 0
4 1
5 1
6 2
7 8
8 20
9 18
10 166
11 397
12 2788
13 5448
14 78102
15 149562
16 2576896
17 6003432
18 91012592
19 257246112
20 5272355344
21 12450552690

List of values

[1, 1, 0, 1, 1, 2, 8, 20, 18, 166, 397, 2788, 5448, 78102, 149562, 2576896, 6003432, 91012592, 257246112, 5272355344, 12450552690]

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

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