A construction of d-optimal weighing designs when n3 mod 4

Abstract A new method is given for constructing D-optimal weighing designs when n 3 mod 4. A matrix of the Goethals-Seidel type is employed and the circulant blocks consist of circular matrices. The new designs, so constructed for n n,k,s )=(23,15,11), (23,16,9), (35,23,11), (35,24,11), (39,23,17), (39,24,12), (39,24,13), (47,29,14), (47,29,15), (47,30,13), (55,31,23), (55,32,16), (55,32,17), (59,35,17), (59,36,16), (59,39,12), (59,40,11), (59,41,11), (71,39,29), (71,40,20), (71,40,21), (71,41,20), (71,41,21), (71,42,19), (83,47,24), (83,48,21), (87,47,35), (87,48,24), (87,48,25), (95,53,26), (95,53,27).