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.

A226437 Number of permutations of {1..n} with fewer than 4 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
6 718
7 4914
8 37300
9 308460
10 2748354
11 26194542
12 265691456
13 2856606480
14 32449828310
15 388371994890
16 4885210675692
17 64439603536980
18 889564376280586
19 12827733624005958
20 192897097090449208
21 3020051018689640760
22 49155675298520617182
23 830625328754347651746

List of values

[1, 1, 2, 6, 24, 120, 718, 4914, 37300, 308460, 2748354, 26194542, 265691456, 2856606480, 32449828310, 388371994890, 4885210675692, 64439603536980, 889564376280586, 12827733624005958, 192897097090449208, 3020051018689640760, 49155675298520617182, 830625328754347651746]

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

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