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.

A319028 Number of permutations pi of [n] such that s(pi) avoids the patterns 132 and 321, where s is West's stack-sorting map.

Table of values

n a(n)
1 1
2 2
3 6
4 22
5 88
6 364
7 1522
8 6374
9 26640
10 110980
11 460716
12 1906172
13 7862416
14 32341144
15 132707626
16 543376774
17 2220650656
18 9060011284
19 36908739316
20 150159618964
21 610186287376
22 2476912674664
23 10044874544116
24 40700948789212
25 164788263075808
26 666716080038824

List of values

[1, 2, 6, 22, 88, 364, 1522, 6374, 26640, 110980, 460716, 1906172, 7862416, 32341144, 132707626, 543376774, 2220650656, 9060011284, 36908739316, 150159618964, 610186287376, 2476912674664, 10044874544116, 40700948789212, 164788263075808, 666716080038824]

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

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