Below are the results of running a program with different size inputs. What is the most likely running time as a function of N

N seconds

$51210\mathrm{.}80$

$1,02412\mathrm{.}00$

$2,04813\mathrm{.}20$

$4,09614\mathrm{.}40$

$8,19215\mathrm{.}60$

$16,38416\mathrm{.}80$

$32,76818\mathrm{.}00$

$65,53619\mathrm{.}20$