Search ProblemsRSS Feed
projecteuler.net

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

Problem 164 Published on Saturday, 20th October 2007, 06:00 am; Solved by 4637;
Difficulty rating: 45%

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?