A sequence a1,a2,a3,… a_1, a_2, a_3, \dots\,a1,a2,a3,… is defined by
a1=1,a2=6an=an−1+an−2,n≥3 \begin{aligned}a_1 &= 1, a_2 = 6 \\a_n &= a_{n-1} + a_{n-2}, \quad n \geq 3\end{aligned} a1an=1,a2=6=an−1+an−2,n≥3Find a3,a4 a_3, a_4\,a3,a4 and a5a_5a5.
