The numbers 1 up to 16 must be placed in the circles of the square depicted below, in such a way that the sum of the numbers in each row, column, and diagonal amounts to 34. How should the numbers be arranged in the square?
The digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 can be arranged into an addition sum to add up to almost any total, except that nobody has yet found a way to add up to 1984. However 9 digits can equal 1984 by an addition sum. Which digit is omitted?
Each empty white square in the grid contains one of the numbers 1, 2, 3,..., 8. Each of the horizontal and vertical equations must be true and each number must be used exactly once.
It can be easily calculated that the digits 0 to 9 can be arranged into 3628800 distinct ten-digit numbers.
But I also know how many of these numbers are prime.
Do you?
