Solve the problem 27 'Quadratic primes'.
Solve the problem 28 'Number spiral diagonals'.
Add a utility script to download problem text.
Solve the problem 29 'Distinct powers'.
problem: give a example of euler problem as comments.
Solve the problem 30 'Digit fifth powers'.
Solve the problem 32 'Coin sums'.
Solve the problem 32 'Pandigital products'.
Coin sum: call iterate() diretly without wrapper.