2015 Countdown Problem #16: Some Brute Force & Luck Needed – Part I

A sequence is defined by the recurrence relation \(u_1=2015\) and \(u_n\) equals the sum of the squares of each digit in \(u_{(n-1)}\) for \(n≥2\).

How many more square numbers than prime numbers are there between \(u_1\) and \(u_{2015}\) inclusive?

#GoodLuckHaveFun

This problem is part of the set 2015 Countdown Problems.

×

Problem Loading...

Note Loading...

Set Loading...