Question 34902
FIRST DIGIT GIVEN = 1
THE NEXT 3 DIGITS CAN BE ANY ONE OF 10 10*10*10 
FIRST LETTER, NOT A VOWEL, THUS WE HAVE 21 OPTIONS
SECOND LETTER - NO RESTRICTIONS, THUS 26 OPTIONS 

SO WE HAVE 1*10*10*10*21*26=546,000 CODING COMBINATIONS.