### 12 Days of Christmas

15^{th}

### 99 Bottles of Beer

23^{rd}

### Abundant Numbers

11^{th}

### Arabic to Roman

12^{th}

### brainfuck

### Christmas Trees

21^{st}

### CSS Colors

12^{th}

### Cubes

16^{th}

### Diamonds

11^{th}

### Divisors

11^{th}

### Emirp Numbers

12^{th}

### Emojify

### Evil Numbers

12^{th}

### Fibonacci

20^{th}

### Fizz Buzz

52^{nd}

### Happy Numbers

21^{st}

### Intersection

6^{th}

### Kolakoski Constant

### Kolakoski Sequence

### Leap Years

14^{th}

### Levenshtein Distance

### Leyland Numbers

12^{th}

### Look and Say

### Lucky Tickets

### Morse Decoder

### Morse Encoder

5^{th}

### Niven Numbers

23^{rd}

### Odious Numbers

8^{th}

### Ordinal Numbers

11^{th}

### Pangram Grep

6^{th}

### Pascal’s Triangle

12^{th}

### Pernicious Numbers

10^{th}

### Poker

### Prime Numbers

29^{th}

### Quine

9^{th}

### Recamán

### Rock-paper-scissors-Spock-lizard

5^{th}

### Roman to Arabic

7^{th}

### Rule 110

### Seven Segment

8^{th}

### Sierpiński Triangle

10^{th}

### Spelling Numbers

### Sudoku

### Ten-pin Bowling

### Tongue-twisters

5^{th}

### United States

16^{th}

### Vampire Numbers

### λ

3^{rd}

### π

7^{th}

### τ

### φ

### √2

### 𝑒

8^{th}