A set of trivial necessary conditions for the existence of a large set of t-designs, LS½Nðt; k; v vÞ, isThere are two conjectures due to Hartman and Khosrovshahi which state that the trivial necessary conditions are sufficient in the cases N ¼ 2 and 3, respectively. Ajoodani-Namini has established the truth of Hartman's conjecture for t ¼ 2. Apart from this celebrated result, we know the correctness of the conjectures for a few small values of k, when N ¼ 2 and t 6, and also when N ¼ 3 and t 4. In this article, we show that similar results can be obtained for infinitely many values of k.