Help solving this problem?

I was wondering if anyone could lend me a hand in starting to solve this question? im relatively new to the program.

Answer 1

[cater re]

an(1) = 2
an(2) = 5
total = 0
for i=3:100
    an(i) = an(i-1) + 2*an(i-2)
    total = total + an(i)
end
plot(3:100, an(3:100))

[Bailey Owen Banks]

Thank you so much!