12 Days of Christmas
Abundant Numbers
Arrows
Christmas Trees
Collatz
Diamonds
Divisors
Emirp Numbers
Evil Numbers
Evil Numbers (Long)
Fibonacci
5,820th1,024th3,654th
Fizz Buzz
Foo Fizz Buzz Bar
Fractions
Intersection
ISBN
Leap Years
Look and Say
Niven Numbers
Niven Numbers (Long)
Number Spiral
Odious Numbers
Odious Numbers (Long)
Ordinal Numbers
Prime Numbers
Quine
φ
√2
𝑒