Question

The function \(f\), defined for whole positive numbers, satisfies \(f(1)=1\) and also the rules \[f(2n)=2f(n),\] \[f(2n+1)=4f(n),\] for all values of \(n\). How many numbers \(n\) satisfy \(f(n)=16\)?

  1. \(3\),

  2. \(4\),

  3. \(5\),

  4. \(6\).