Two Generalizations of the Metamorphosis Definitaion

Abstract

Let B(k, y.) be the spectrum of integers n such that there exists a Sy {2, k, n), a balanced incomplete block design of order n, block size k and index y.. Lindner and Rosa [6) introduced the definition of a Sy.(2, 4, n) having f\ metamorphosis into a Sy.(2, 3, n) Rnd proved that the necessary condition n E B(a, >.) n B(4, >.) is also sufficient .