(Again copied verbatim from a September 2009 thread I made.)
A Primally Magic Square (PMS) is exactly like a traditional magic square with a change of criteria. Where a traditional magic square is one where the sum of each row, column, and both diagonals are some number, usually 15 (uses 1-9). By contrast, a PMS is one where all rows, columns, and both diagonals form a prime number. Note: if a number is prime either forward or back, it counts.
Example:
$\displaystyle \begin{matrix} 1 & 3 & 7 \\ 3 & 9 & 7 \\ 7 & 7 & 9 \end{matrix}$
137, 397, 977, 797, and 199 are all prime, so this square is a PMS.
How many 3x3 PMS's are there?
How many 4x4 PMS's are there?
How many 5x5 PMS's are there?
How many 9x9 PMS's are there?
Side note: Feel free to calculate the number of PMS's for some other $n$.