Abundant Numbers
790
Arithmetic Numbers
791
Card Number Validation
571
Catalan Numbers
663
Christmas Trees
721
Collatz
844
CSS Colors
123
Day of Week
895
Emirp Numbers
439
Emirp Numbers (Long)
525
Evil Numbers
642
Fizz Buzz
989
Leap Years
892
Niven Numbers
658
Pangram Grep
683
Prime Numbers
647
Tongue-twisters
341