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.

A246246 Number of permutations of [n] with exactly one occurrence of the consecutive step pattern up, down, down.

Table of values

n a(n)
4 3
5 30
6 270
7 2322
8 20772
9 195372
10 1958337
11 20933154
12 238789782
13 2900868876
14 37451986200
15 512534035080
16 7416327050415
17 113185393797510
18 1817654015037150
19 30647027466113094
20 541407973316966604
21 10001886705503187732
22 192877025408450517501
23 3876090406516703418282

List of values

[3, 30, 270, 2322, 20772, 195372, 1958337, 20933154, 238789782, 2900868876, 37451986200, 512534035080, 7416327050415, 113185393797510, 1817654015037150, 30647027466113094, 541407973316966604, 10001886705503187732, 192877025408450517501, 3876090406516703418282]

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

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