Fibonacci Numbers and Their Lucas Coefficients

Abstract

We show that for the classical Fibonacci sequence (Fn) and the Lucas sequence (Ln) the following identity holds for every integer n >= 2: (n-1)Fn equals the sum from k=1 to n-1 of Lk multiplied by F(n-k). Equivalently, this gives a representation of the nth Fibonacci number as Fn = (1 / (n-1)) times the same sum. We present a detailed proof by mathematical induction and illustrate the identity with a numeric example.