## Abstract

We consider the problem of k robots searching on an integer lattice on the plane. We give a strategy for finding a target at an unknown distance away using k=2^{j}searchers, where j ≥ 2, at a competitive ratio of n/2

^{j-1}+1. We give a lower bound for general k of 2n/k. We also give matching upper and lower bounds for the special case k=2.