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.

A102381 Number of permutations of 1..n in which every pair of adjacent numbers as well as the first and the last entries are relatively prime.

Table of values

n a(n)
1 1
2 2
3 6
4 8
5 60
6 24
7 504
8 576
9 6480
10 5760
11 242352
12 93312
13 6200064
14 5612544
15 95294880
16 136249344
17 13687492608
18 5022425088
19 693149184000
20 472559616000
21 18501259714560
22 23441203298304
23 4435759798272000
24 1568692666368000
25 262234601210880000
26 317576826394214400

List of values

[1, 2, 6, 8, 60, 24, 504, 576, 6480, 5760, 242352, 93312, 6200064, 5612544, 95294880, 136249344, 13687492608, 5022425088, 693149184000, 472559616000, 18501259714560, 23441203298304, 4435759798272000, 1568692666368000, 262234601210880000, 317576826394214400]

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

Content is available under The OEIS End-User License Agreement.