In a certain sequence, the next term is found by taking the number before it minus the number two numbers before it.

For example, in the sequence a, b, c, d... c = b-a, d = c-b, and so on.

Starting with 54 and 93, what would be the sum of the first six thousand terms?

(In reply to

Solution by Popstar Dave)

I forget to mention that this answer stands for any two inital values.

For any two starting values a and b, the six term, repeating pattern will be:

a, b, (b-a), -a, -b, (a-b).

Therefore the sum of any sequential, multiple of six terms will be zero.