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Super-integers and divisors of super-zero

Source: Problem 5 - Brazil Math Olympiad 1994

March 17, 2006
number theory unsolvednumber theory

Problem Statement

Call a super-integer an infinite sequence of decimal digits: dnd2d1\ldots d_n \ldots d_2d_1.
(Formally speaking, it is the sequence (d1,d2d1,d3d2d1,)(d_1,d_2d_1,d_3d_2d_1,\ldots) )
Given two such super-integers cnc2c1\ldots c_n \ldots c_2c_1 and dnd2d1\ldots d_n \ldots d_2d_1, their product pnp2p1\ldots p_n \ldots p_2p_1 is formed by taking pnp2p1p_n \ldots p_2p_1 to be the last n digits of the product cnc2c1c_n \ldots c_2c_1 and dnd2d1d_n \ldots d_2d_1. Can we find two non-zero super-integers with zero product? (a zero super-integer has all its digits zero)