Double counting kid

Last weekend, on Sunday morning, the 7-year old crawled into our bed and told me what he had been up to that morning. Turned out he was just playing with figures and doing some "double counting" as he called it. He basically calculated the powers of 2 up till 256. So he went 1 + 1 = 2; 2 + 2 = 4; 4 + 4 = 8, et cetera. But the interesting part of this was that instead of starting from 1 he started from a quarter.

He must be destined for a life as a programmer (or an accountant)

Zaaf