%I

%S 1,6,168,26880

%N Number of orthogonal cocycles in Z^2(Z^t_2,Z_2).

%D Horadam, K. J., Hadamard matrices and their applications. Princeton University Press, Princeton, NJ, 2007. xiv+263 pp. See p. 132.

%K nonn,more

%O 1,2

%A _N. J. A. Sloane_, Feb 05 2012