A014582 Orders of magic squares whose rows and columns all have different sum-of-squares values (except for the necessary 180-degree symmetry).
3, 23, 43, 47, 61, 67, 113, 127, 137, 149, 173, 193, 199
Offset: 1
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.