Wolfram Research
Wolfram Math World: Prime Number
Prime Numbers are defined with a glossary hyperlink to terms used in the definition. Lots of information and examples included. Lists many math-related links. Scroll down to the bottom of the page to see how prime numbers are used in the...
University of Cambridge
University of Cambridge: Nrich: Two Primes Make One Square
On this one page website sharpen your logic, prime numbers and square numbers skills while working on this challenge. The solution is available to double check your solution.