Project Euler 684 - Inverse Digit Sum

Official link:

Thought Process

A whole lot of algebraic manipulation is coming up ahead, so if you don't like mathematical symbols I suggest you move to another problem

I'm sure that there are many ways to manipulate the geometric series, however I found this to be the one that made the most sense to me!

All I need to do now is to generate the first 90 Fibonacci numbers (See my essential functions)

Interactive Code

Enter a number (yourinput)

Code will output S(yourinput)