A355256 a(n) is the number of n-th order n X n magic arrays composed of the numbers from 1 to n^2 in which each 2 X 2 subsquare has the same sum, counted up to rotations and reflections.
1, 3, 47, 2544, 6480, 5510592
Offset: 1
Examples
For n = 2 the a(2) = 3 solutions are (1 2; 3 4), (1 2; 4 3) and (1 3; 4 2).
Links
- Donghwi Park, Source code for a(1) to a(5).
- Donghwi Park, Source code for a(6).
Extensions
a(6) from Donghwi Park, Aug 06 2025