Project Euler 114 - Counting Block Combinations I

Official link: https://projecteuler.net/problem=114

Harder version of Problem 117 and Problem 116

Thought Process

For problems like this we want to build a Recurrence Relation

From here a simple recursion formula will do as we know the inital values

Interactive Code

Enter the length of the row (yourinput)

Code will output the answer for a row size yourinput