MathDB
n^k ends in a 2012-string of 1's

Source: Problem 3, Brazilian MO, 2012

November 28, 2012
modular arithmeticinductionnumber theory unsolvednumber theory

Problem Statement

Find the least non-negative integer nn such that exists a non-negative integer kk such that the last 2012 decimal digits of nkn^k are all 11's.