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.

A317111 Number of permutations of [n] in which the length of every increasing run is 0 or 1 (mod 4).

Table of values

n a(n)
0 1
1 1
2 1
3 1
4 2
5 10
6 50
7 210
8 840
9 4200
10 29400
11 231000
12 1755600
13 13213200
14 109309200
15 1051050000
16 11099088000
17 120071952000
18 1320791472000
19 15317750448000
20 192286654560000
21 2577944809440000
22 35885904294240000
23 513695427204960000
24 7641940962015360000

List of values

[1, 1, 1, 1, 2, 10, 50, 210, 840, 4200, 29400, 231000, 1755600, 13213200, 109309200, 1051050000, 11099088000, 120071952000, 1320791472000, 15317750448000, 192286654560000, 2577944809440000, 35885904294240000, 513695427204960000, 7641940962015360000]

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

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