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.

A183820 1/256 the number of (n+1)X(n+1) 0..3 arrays with no 2X2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor.

Table of values

n a(n)
1 1
2 813
3 8538066
4 1163575148283
5 2051388696859571241

List of values

[1, 813, 8538066, 1163575148283, 2051388696859571241]

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

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