______          __          ______          
  / ____/___  ____/ /__  _____/ ____/_  ______ 
 / /   / __ \/ __  / _ \/ ___/ /   / / / / __ \
/ /___/ /_/ / /_/ /  __/ /  / /___/ /_/ / /_/ /
\____/\____/\__,_/\___/_/   \____/\__,_/ .___/ 
                                      /_/ 
        

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Numbers for which no three consecutive digits have a sum greater than a given value

Of the first 10 submissions producing the correct answer, one will be randomly selected to win $100. The winning solution will be shared for others to learn from. Please remember to add your code or methodology after submitting the answer if you would like to eligible for the prize. Submissions for prize money are open until 02-21-2020, 00:00:00 UTC.

How many 20 digit numbers n (without any leading zero) exist such that no three consecutive digits of n have a sum greater than 9?

https://projecteuler.net/problem=164