Which prime, below one-million, can be written as the sum of the most consecutive primes?
Find the smallest prime which, by changing the same part of the number, can form eight different primes.
Find the smallest positive integer, x, such that 2x, 3x, 4x, 5x, and 6x, contain the same digits in some order.
How many values of C(n,r), for 1 ≤ n ≤ 100, exceed one-million?
How many hands did player one win in the game of poker?
How many Lychrel numbers are there below ten-thousand?
Considering natural numbers of the form, ab, finding the maximum digital sum.
Investigate the expansion of the continued fraction for the square root of two.
Investigate the number of primes that lie on the diagonals of the spiral grid.
Using a brute force attack, can you decrypt the cipher using XOR encryption?