Numbers with a Given Prime Factor Sum
Consider the numbers $15$, $16$ and $18$: $15=3\times 5$ and $3+5=8$. $16 = 2\times 2\times 2\times 2$ and $2+2+2+2=8$. $18 = 2\times 3\times 3$ and $2+3+3=8$. $15$,...