12 Days of Christmas
            
                        
                    14th
        
            Christmas Trees
            
                        
                    15th
        
            Diamonds
            
                        
                    19th
        
            Divisors
            
                        
                    29th
        
            Emirp Numbers
            
                        
                    15th
        
            Evil Numbers
            
                        
                    15th
        
            Fibonacci
            
                        
                    48th
        
            Fizz Buzz
            
                        
                    61st
        
            Happy Numbers
            
                        
                    15th
        
            Niven Numbers
            
                        
                    36th
        
            Odious Numbers
            
                        
                    18th
        
            Pangram Grep
            
                        
                    48th
        
            Pascal’s Triangle
            
                        
                    28th
        
            Pernicious Numbers
            
                        
                    26th
        
            Prime Numbers
            
                        
                    29th
        
            Quine
            1st
                        
                    
        
            π
            
                        
                    14th
        
            τ
            
                        
                    12th