%I #24 Apr 11 2012 11:16:18
%S 1,8,24,120,264,240,648,576
%N Number of Williamson Hadamard matrices over Z_(2*n+1) X Z^2_2.
%C The precise form of Williamson Hadamard matrix is given by Eq. (12) on page 131 of [Baliga, et al.].
%H A. Baliga and K. J. Horadam, <a href="http://ajc.maths.uq.edu.au/pdf/11/ocr-ajc-v11-p123.pdf">Cocyclic Hadamard matrices over Z_t X Z^2_2</a>, Australas. J. Combin. 11(1995), 123-134.
%Y Cf. A182083.
%K nonn,hard,more
%O 0,2
%A _L. Edson Jeffery_, Apr 10 2012