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.

A383770 Number of nonnesting permutations of [n] avoiding 231 (and by symmetry 132, 213, or 312).

Table of values

n a(n)
0 1
1 1
2 4
3 17
4 77
5 367
6 1815
7 9233
8 48014
9 254123
10 1364491
11 7414733
12 40701346
13 225359021
14 1257148285
15 7058816337
16 39863261170
17 226270553575
18 1290212119208
19 7387057794679
20 42450966727899
21 244771835135261
22 1415678529391032
23 8210790845555365
24 47744558865042855

List of values

[1, 1, 4, 17, 77, 367, 1815, 9233, 48014, 254123, 1364491, 7414733, 40701346, 225359021, 1257148285, 7058816337, 39863261170, 226270553575, 1290212119208, 7387057794679, 42450966727899, 244771835135261, 1415678529391032, 8210790845555365, 47744558865042855]

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

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