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.

A117542 Number of permutations P of 1..n such that in P and in the inverse of P, every pair of adjacent numbers and the first and last number, are relatively prime.

Table of values

n a(n)
1 1
2 2
3 6
4 8
5 36
6 16
7 127
8 320
9 581
10 1564
11 13565
12 13760
13 149186
14 773727
15 540538

List of values

[1, 2, 6, 8, 36, 16, 127, 320, 581, 1564, 13565, 13760, 149186, 773727, 540538]