12 Days of Christmas
249th
Abundant Numbers
324th
Christmas Trees
80th
Diamonds
443rd
Divisors
1st
Emirp Numbers
213th
Evil Numbers
441st
Fibonacci
154th
Fizz Buzz
643rd
Happy Numbers
508th
Leap Years
387th
Leyland Numbers
297th
Morse Decoder
108th
Morse Encoder
104th
Niven Numbers
58th
Odious Numbers
255th
Ordinal Numbers
169th
Pangram Grep
45th
Pascal’s Triangle
1st
Pernicious Numbers
239th
Prime Numbers
434th
Recamán
156th
Rock-paper-scissors-Spock-lizard
75th
Seven Segment
133rd
Sierpiński Triangle
53rd
φ
108th
√2
320th
𝑒
215th