%I #4 Mar 30 2012 16:45:52
%S 1,12,108,2593,225900
%N (2n+1,3,9) difference families over Z_{2n+1}.
%D CRC Handbook of Combinatorial Designs, 1996, p. 285.
%K nonn,hard
%O 2,2
%A _N. J. A. Sloane_.
