2,3

C. Koukouvinos and S. Stylianou, On skew-Hadamard matrices, Discrete Math., 308 (2008), 2723-2731.

Spence, Edward; Classification of Hadamard matrices of order 24 and 28. Discrete Math. 140 (1995), no. 1-3, 185-243.

Sequence in context: A076615 A098777 A127226 this_sequence A062282 A012319 A012520

Adjacent sequences: A001116 A001117 A001118 this_sequence A001120 A001121 A001122

nonn,hard,nice

njas