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.

A053617 Number of permutations of length n which avoid the patterns 1234 and 1324.

Table of values

n a(n)
0 1
1 1
2 2
3 6
4 22
5 90
6 396
7 1837
8 8864
9 44074
10 224352
11 1163724
12 6129840
13 32703074
14 176351644
15 959658200
16 5262988330
17 29057961666
18 161374413196
19 900792925199
20 5050924332096
21 28434661250454
22 160644331001476
23 910455895039056
24 5174722258676440
25 29486753617569684

List of values

[1, 1, 2, 6, 22, 90, 396, 1837, 8864, 44074, 224352, 1163724, 6129840, 32703074, 176351644, 959658200, 5262988330, 29057961666, 161374413196, 900792925199, 5050924332096, 28434661250454, 160644331001476, 910455895039056, 5174722258676440, 29486753617569684]

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

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