The existence spectrum for (3,λ)(3,λ)-GDDs of type gtu1gtu1

The necessary and sufficient conditions for the existence of a (3,1)(3,1)-GDD of type gtu1gtu1 have been established by Colbourn et al. In this paper, the existence of a (3,λ)(3,λ)-GDD of type gtu1gtu1 for any λ≥2λ≥2 is investigated. Finally, its existence spectrum is completely determined.