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.

A226440 Number of permutations of {1..n} with fewer than 7 interior elements having values lying between the values of their neighbors.

Table of values

n a(n)
0 1
1 1
2 2
3 6
4 24
5 120
6 720
7 5040
8 40320
9 362878
10 3627778
11 39830282
12 475089392
13 6094561180
14 83333937940
15 1205398303180
16 18331873363480
17 291706615484450
18 4838414115229430
19 83404373736108502
20 1490681666580459304
21 27572241018065482032
22 526959942343051879032

List of values

[1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362878, 3627778, 39830282, 475089392, 6094561180, 83333937940, 1205398303180, 18331873363480, 291706615484450, 4838414115229430, 83404373736108502, 1490681666580459304, 27572241018065482032, 526959942343051879032]

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

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