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.

A111285 Number of permutations avoiding the patterns {2431, 3421, 4231, 4321, 24513, 42513, 34512, 43512}; number of strong sorting class based on 2431.

Table of values

n a(n)
0 1
1 1
2 2
3 6
4 20
5 66
6 216
7 706
8 2308
9 7546
10 24672
11 80666
12 263740
13 862306
14 2819336
15 9217906
16 30138228
17 98537866
18 322172592
19 1053353226
20 3443970860
21 11260168946
22 36815469656
23 120369313506
24 393551182948
25 1286727730586
26 4206996000512

List of values

[1, 1, 2, 6, 20, 66, 216, 706, 2308, 7546, 24672, 80666, 263740, 862306, 2819336, 9217906, 30138228, 98537866, 322172592, 1053353226, 3443970860, 11260168946, 36815469656, 120369313506, 393551182948, 1286727730586, 4206996000512]

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

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