A 9 Solution of (A 9) is given by g n = ( ϕ λ ) n g 0 = x n g 0, A 10 where x = ϕ/λ.
A 4 Rearranging terms yields − s 2 b n n + s ( f n n − b n ( λ + ϕ ) ) + ( λ + ϕ ) f n = ϕ f n − 1 + λ f n + 1 − s ( ϕ b n − 1 + λ b n + 1 ).