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.

A258213 Number of permutations of {1,2,3,...,n} such that no even numbers are adjacent.

Table of values

n a(n)
0 1
1 1
2 2
3 6
4 12
5 72
6 144
7 1440
8 2880
9 43200
10 86400
11 1814400
12 3628800
13 101606400
14 203212800
15 7315660800
16 14631321600
17 658409472000
18 1316818944000
19 72425041920000
20 144850083840000
21 9560105533440000
22 19120211066880000
23 1491376463216640000
24 2982752926433280000

List of values

[1, 1, 2, 6, 12, 72, 144, 1440, 2880, 43200, 86400, 1814400, 3628800, 101606400, 203212800, 7315660800, 14631321600, 658409472000, 1316818944000, 72425041920000, 144850083840000, 9560105533440000, 19120211066880000, 1491376463216640000, 2982752926433280000]

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

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