A projective plane of order q consists of a set q2+q+1 points and a set of q2+q+1 lines, there are exactly q+1 points on each line and q+1 lines pass through each point. A blocking set B. A blocking set V is the complement of a (k,n) – arc K with t=q+1-n. In this paper, non-existence of some (k,n)-arcs are proved for q=73