I always count myself as being among those who are mathematically challenged. Consequently I hold in awe anyone with ability to count up to 100 or multiply 4X4.
By my standards, this puzzlist ought to be anointed and hailed as the most exalted divinity. The square shown above is not an ordinary one.
Each row and column adds to the same sum — but so is each successive nested square, from 11 x 11 down to 3 x 3.
The magic constant of each square is 10,874 smaller than the last.
And every cell is prime.
Apparently this was composed by someone who was spending time in the prison.
Found it here- http://bit.ly/dw9S2G