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.

A226435 Number of permutations of {1..n} with fewer than 2 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 22
5 90
6 422
7 2226
8 13102
9 85170
10 606542
11 4697946
12 39330982
13 353985450
14 3408792662
15 34975509666
16 380947661662
17 4390028664930
18 53368010874782
19 682564606249386
20 9162253729773142
21 128794752680027610
22 1892150024227428902
23 28998220554100469106

List of values

[1, 1, 2, 6, 22, 90, 422, 2226, 13102, 85170, 606542, 4697946, 39330982, 353985450, 3408792662, 34975509666, 380947661662, 4390028664930, 53368010874782, 682564606249386, 9162253729773142, 128794752680027610, 1892150024227428902, 28998220554100469106]

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

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