12 Days of Christmas
417
Abundant Numbers
742
Arabic to Roman
642
Christmas Trees
607
CSS Colors
905
Diamonds
577
Divisors
947
Emirp Numbers
743
Evil Numbers
816
Factorial Factorisation
562
Fibonacci
947
Fizz Buzz
898
Gijswijt’s Sequence
688
Happy Numbers
516
ISBN
628
Kaprekar Numbers
744
Leap Years
843
Levenshtein Distance
476
ln 2
813
Morse Decoder
489
Morse Encoder
461
Niven Numbers
957
Odious Numbers
800
Ordinal Numbers
717
Pangram Grep
792
Pascal’s Triangle
602
Pernicious Numbers
755
Prime Numbers
909
Quine
969
Rijndael S-box
809
Seven Segment
587
Sierpiński Triangle
134
Tongue-twisters
279
United States
627
π
841