Group divisible designs with two associate classes and λ2 =1

Abstract

The original classiffcation of PBIBDs defined group divisible designs GDD(ν= ν1 + ν2 +⋯+ νg,g,k, λ1, λ2) with λ1 ≠ 0. In this paper, we prove that the necessary conditions are suffcient for the existence of the group divisible designs with two groups of unequal sizes and block size three with λ2 =1. Copyright 2011 Nittiya Pabhapote and Narong Punnim.