MathDB

sequence of numbers +1 and -1 of length n (2018 Auckland MO S5)

Source:

November 15, 2021

algebra

Problem Statement

There is a sequence of numbers

+1

and

-1

of length

n

. It is known that the sum of every

10

neighbouring numbers in the sequence is

0

and that the sum of every

12

neighbouring numbers in the sequence is not zero. What is the maximal value of

n