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.

A030227 Number of achiral polyominoes with n cells.

Table of values

n a(n)
0 1
1 1
2 1
3 2
4 3
5 6
6 10
7 20
8 34
9 70
10 121
11 250
12 441
13 912
14 1630
15 3375
16 6092
17 12624
18 22961
19 47616
20 87136
21 180811
22 332549
23 690398
24 1275166
25 2648422
26 4909364
27 10199792
28 18966700
29 39416488
30 73497642
31 152777230
32 285569898
33 593717419
34 1112188817
35 2312672439
36 4340728280

List of values

[1, 1, 1, 2, 3, 6, 10, 20, 34, 70, 121, 250, 441, 912, 1630, 3375, 6092, 12624, 22961, 47616, 87136, 180811, 332549, 690398, 1275166, 2648422, 4909364, 10199792, 18966700, 39416488, 73497642, 152777230, 285569898, 593717419, 1112188817, 2312672439, 4340728280]