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.

A123783 Number of ways to build a contiguous building with n LEGO blocks of size 1 X 4 on top of a fixed block of the same size so that the building is symmetric after a rotation by 180 degrees.

Table of values

n a(n)
1 1
2 11
3 21
4 248
5 712
6 9182
7 28297
8 375483
9 1266013

List of values

[1, 11, 21, 248, 712, 9182, 28297, 375483, 1266013]

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

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