Group divisible designs with block size 4 and group sizes 2 and 5

R. Julian R. Abel, Thomas Britz, Yudhistira A. Bunjamin +1

In this paper we provide a $4$-GDD of type $2^2{5}^5$, thereby solving the existence question for the last remaining feasible type for a $4$-GDD with no more than $30$ points. We th…