Starting with 500 and creating a pattern that subtracts 4 from each number would give us an expression of x = n - 4 where x is the next number in progression and n is the current number. Using this expression we get the following sequence out to 5 numbers. 500, (500-4)=496, (496-4)=492, (492-4)=488, (488-4)=484. The final sequence is 500, 496, 492, 488, 484.