### 12 Days of Christmas

29^{th}

### 99 Bottles of Beer

21^{st}

### Abundant Numbers

11^{th}

### Arabic to Roman

11^{th}

### Brainfuck

### CSS Colors

### Christmas Trees

17^{th}

### Cubes

15^{th}

### Diamonds

10^{th}

### Divisors

9^{th}

### Emirp Numbers

11^{th}

### Evil Numbers

12^{th}

### Fibonacci

13^{th}

### Fizz Buzz

42^{nd}

### Happy Numbers

17^{th}

### Leap Years

10^{th}

### Leyland Numbers

### Lucky Tickets

### Morse Decoder

### Morse Encoder

### Niven Numbers

20^{th}

### Odious Numbers

9^{th}

### Ordinal Numbers

7^{th}

### Pangram Grep

5^{th}

### Pascal’s Triangle

13^{th}

### Pernicious Numbers

10^{th}

### Poker

### Prime Numbers

24^{th}

### Quine

8^{th}

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

5^{th}

### Roman to Arabic

6^{th}

### Rule 110

### Seven Segment

8^{th}

### Sierpiński Triangle

9^{th}

### Spelling Numbers

### Sudoku

### Ten-pin Bowling

### United States

14^{th}

### λ

### π

6^{th}

### τ

### φ

### √2

### 𝑒

7^{th}