If k is a non-negative constant, then the solution to the recurrence
$T(n) = \begin{cases} 1 & \quad n=1 \\ 3T(n/2) + n & \quad n>1 \end{cases} $
for $n$, a power of 2 is
- $T(n) = 3^{\log_2 n} - 2n$
- $T(n) = 2 \times 3^{\log_2 n} - 2n$
- $T(n) = 3 \times 3^{\log_2 n} - 2n$
- $T(n) = 3 \times 3^{\log_2 n} - 3n$