Showing what's behind the curtain

Find how many Pythagorean triangles allow tiling with a perimeter < 100,000,000.

The prime factorisation of binomial coefficients

Powers With Trailing Digits

Comparing four-sided and six-sided dice

Find the sum of the distinct square-free numbers in the first 51 rows of Pascal’s triangle.

Find the unique positive integer for a concealed square.

Skew-cost coding

Tribonacci non-divisors

An Arithmetic Geometric sequence

Odd triplets in Pascal’s triangle.