12 Days of Christmas
121st
Abundant Numbers
375th
Christmas Trees
137th
Diamonds
167th
Divisors
108th
Emirp Numbers
258th
Evil Numbers
458th
Fibonacci
163rd
Fizz Buzz
697th
Happy Numbers
541st
Leap Years
411th
Leyland Numbers
314th
Morse Decoder
113th
Morse Encoder
111th
Niven Numbers
64th
Odious Numbers
273rd
Ordinal Numbers
199th
Pangram Grep
109th
Pascal’s Triangle
41st
Pernicious Numbers
260th
Prime Numbers
474th
Recamán
190th
Rock-paper-scissors-Spock-lizard
98th
Seven Segment
167th
Sierpiński Triangle
77th
φ
145th
√2
350th
𝑒
236th