Regularity versus complexity in the binary representation of 3^n

Eric S. Rowland

Published 2009-02-18, updated 2010-03-12Version 2

We use the grid consisting of bits of 3^n to motivate the definition of 2-adic numbers. Specifically, we exhibit diagonal stripes in the bits of 3^(2^n), which turn out to be the first in an infinite sequence of such structures. Our observations are explained by a 2-adic power series, providing some regularity among the disorder in the bits of powers of 3. Generally, the base-p representation of k^(p^n) has these features.