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.

A123819 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 2 X 2 which is symmetric after a rotation by 180 degrees.

Table of values

n a(n)
1 1
2 1
3 5
4 8
5 65
6 126
7 1023
8 2187
9 17585
10 39606
11 315326
12 737302

List of values

[1, 1, 5, 8, 65, 126, 1023, 2187, 17585, 39606, 315326, 737302]