Let
a_0=5
a_1=5
a_n=a_(n-1)+a_(n-2) for n>=2 There is a unique ordered pair (c,d) such that \($c\phi^n + d\widehat{\phi}^n$ \) is the closed form for sequence a_n . Find c using the Fibonacci and Lucas number sequences.
c = 4 + 4*sqrt(5)/5.
