Find the minimal path sum from the left column to the right column.
Find the value of d < 1000 for which 1/d contains the longest recurring cycle.
Investigate the number of primes that lie on the diagonals of the spiral grid.
Find the sum of all numbers less than one million, which are palindromic in base 10 and base 2.
Useful tools, files and routines to help solve problems on Project Euler