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Abundant Numbers

Abundant Numbers (Long)

Arabic to Roman

Christmas Trees

Collatz

Diamonds

Divisors

Evil Numbers

Evil Numbers (Long)

Fibonacci

Fizz Buzz

Foo Fizz Buzz Bar

Fractions

Happy Numbers

Happy Numbers (Long)

Intersection

ISBN

Leap Years

Niven Numbers

Niven Numbers (Long)

Odious Numbers

Odious Numbers (Long)

Ordinal Numbers

Pernicious Numbers

Pernicious Numbers (Long)

Prime Numbers

Prime Numbers (Long)

Tongue-twisters