Completing the spectrum for LGDD (mv)

Abstract

In this article, we construct LGDD(mv) for v ≡ 2 (mod 6) and m ≡ 0 (mod 6) by constructing the missing essential values 6v, v = 8, 14, 26, 50. Thus an LGDD(mv) exists if and only if v(v - 1)m2 ≡ 0 (mod 6), (v - 1)m ≡ 0 (mod 2) and (m, v) ≠ (1, 7). © 1997 John Wiley & Sons, Inc.