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.

A123773 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 3 which is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees.

Table of values

n a(n)
1 1
2 1
3 3
4 4
5 16
6 24
7 103
8 163
9 721
10 1173
11 5283
12 8783
13 39912
14 67381
15 308314
16 526553
17 2421040
18 4172834
19 19257309
20 33438244
21 154761065
22 270372085

List of values

[1, 1, 3, 4, 16, 24, 103, 163, 721, 1173, 5283, 8783, 39912, 67381, 308314, 526553, 2421040, 4172834, 19257309, 33438244, 154761065, 270372085]

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

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