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.

A000303 Number of permutations of [n] in which the longest increasing run has length 2.

Table of values

n a(n)
1 0
2 1
3 4
4 16
5 69
6 348
7 2016
8 13357
9 99376
10 822040
11 7477161
12 74207208
13 797771520
14 9236662345
15 114579019468
16 1516103040832
17 21314681315997
18 317288088082404
19 4985505271920096
20 82459612672301845
21 1432064398910663704
22 26054771465540507272

List of values

[0, 1, 4, 16, 69, 348, 2016, 13357, 99376, 822040, 7477161, 74207208, 797771520, 9236662345, 114579019468, 1516103040832, 21314681315997, 317288088082404, 4985505271920096, 82459612672301845, 1432064398910663704, 26054771465540507272]

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

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