## Elastic Numbers

It’s here! My new book of puzzles Elastic Numbers is now available on Amazon.

https://www.amazon.co.uk/Elastic-Numbers-Puzzles-Serious-Problem/dp/0995782601

https://www.amazon.com/gp/aw/d/0995782601

I hope you enjoy solving the problems as much as I enjoyed creating them.

It is given that $2^{2004}$ is a 604-digit number beginning with a 1. How many of the numbers $2^0, 2^1, 2^2, 2^3, ..., 2^{2003}$ begin with a 4?