A146555 Number of n X n arrays of squares of integers summing to 40 with every element equal to at least one neighbor.
4, 128, 120672, 102504963, 209207867680
Offset: 2
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.