MathDB
Sequences Modulo 11: Indexblocked

Source: 2018 AIME II #2

March 23, 2018
abstract algebraAMCAIMEAIME II

Problem Statement

Let a0=2a_0 = 2, a1=5a_1 = 5, and a2=8a_2 = 8, and for n>2n>2 define ana_n recursively to be the remainder when 4(an1+an2+an3)4(a_{n-1} + a_{n-2} + a_{n-3}) is divided by 1111. Find a2018a2020a2022a_{2018}\cdot a_{2020}\cdot a_{2022}.