Showing what's behind the curtain

Find the 2000th hexagonal tile in which the differences between it and its 6 neighbors yield 3 primes.

The prime factorisation of binomial coefficients

Powers With Trailing Digits

Prime Subset Sums

Find the number of non-empty subsets of {1^{1}, 2^{2}, 3^{3},…, 250250^{250250}}, the sum of whose elements is divisible by 250.

Determining the value of infinite polynomial series for which the coefficients are Fibonacci numbers.

Calculating the sum of the decimal digits of irrational square roots.

Investigate the Diophantine equation *x*^{2} − D*y*^{2} = 1.

Investigating which primes will never divide a repunit containing 10**n digits.

Find the base/exponent pair in the file has the greatest numerical value