Group Divisible Designs with Two Associate Classes and λ2=1

الملخص EN

The original classiffcation of PBIBDs defined group divisible designs GDD(v=v1+v2+⋯+vg,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.