12 Days of Christmas
51st
99 Bottles of Beer
52nd
Abundant Numbers
60th
Arrows
43rd
CSS Colors
29th
Diamonds
168th
Divisors
88th
Emirp Numbers
16th
Evil Numbers
79th
144th
Fibonacci
183rd
197th
Fizz Buzz
223rd
1st
222nd
Happy Numbers
17th
56th
Leap Years
171st78th
37th
68th107th
51st
337th
Leyland Numbers
20th
Lucky Tickets
24th
Morse Decoder
53rd
Morse Encoder
46th
Niven Numbers
1st
157th
Odious Numbers
77th
317th
Ordinal Numbers
75th
Pangram Grep
Pascal’s Triangle
68th
Pernicious Numbers
65th
174th
Prime Numbers
1st
363rd
Quine
1st25th105th1st85th26th67th125th5th75th33rd1st1st47th122nd49th38th82nd44th100th
Rule 110
61st
Seven Segment
84th
Spelling Numbers
20th
United States
λ
49th
29th
39th48th42nd158th19th
π
53rd
τ
50th
φ
77th
√2
90th
𝑒
89th