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.

A230557 The number of 123-avoiding simple involutions of length n.

Table of values

n a(n)
1 1
2 2
3 0
4 0
5 2
6 3
7 2
8 5
9 10
10 17
11 22
12 44
13 68
14 127
15 184
16 356
17 530
18 1017
19 1502
20 2906
21 4312
22 8351
23 12388
24 24067
25 35748
26 69577
27 103404
28 201642
29 299882
30 585691
31 871498
32 1704509
33 2537522
34 4969153
35 7400782
36 14508938
37 21617096
38 42422023
39 63226948
40 124191257
41 185155568
42 363985681
43 542815792
44 1067892398
45 1592969006

List of values

[1, 2, 0, 0, 2, 3, 2, 5, 10, 17, 22, 44, 68, 127, 184, 356, 530, 1017, 1502, 2906, 4312, 8351, 12388, 24067, 35748, 69577, 103404, 201642, 299882, 585691, 871498, 1704509, 2537522, 4969153, 7400782, 14508938, 21617096, 42422023, 63226948, 124191257, 185155568, 363985681, 542815792, 1067892398, 1592969006]