I like to waste my time on long-standing unsolved problems - the choice this week is the square-free nature of $1+p_n\#$, where $p_n\#$ is the $n$-th primorial.
The question here is short: does anyone know of a heuristic to measure potential proofs regarding this statement or others like it against?
(I'm nowhere close to a proof but if I want to get there I should know what I'm up against... Thanks in advance!!)