Abundant Numbers
791
Arithmetic Numbers
793
Card Number Validation
574
Catalan Numbers
665
Christmas Trees
721
Collatz
846
CSS Colors
123
Day of Week
897
Emirp Numbers
439
Emirp Numbers (Long)
528
Evil Numbers
642
Fizz Buzz
989
Leap Years
892
Niven Numbers
659
Pangram Grep
684
Prime Numbers
648
Tongue-twisters
342