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.

A226430 The number of simple permutations of length n which avoid 1243 and 2431.

Table of values

n a(n)
1 1
2 2
3 0
4 2
5 4
6 10
7 21
8 44
9 89
10 178
11 352
12 692
13 1355
14 2648
15 5171
16 10100
17 19744
18 38646
19 75761
20 148772
21 292653
22 576678
23 1138240
24 2250152
25 4454679
26 8830640
27 17525991
28 34820264
29 69244864
30 137815978
31 274487517
32 547035452
33 1090790465
34 2176043098
35 4342753696
36 8669805020
37 17313228899

List of values

[1, 2, 0, 2, 4, 10, 21, 44, 89, 178, 352, 692, 1355, 2648, 5171, 10100, 19744, 38646, 75761, 148772, 292653, 576678, 1138240, 2250152, 4454679, 8830640, 17525991, 34820264, 69244864, 137815978, 274487517, 547035452, 1090790465, 2176043098, 4342753696, 8669805020, 17313228899]

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

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