%I #5 Mar 30 2012 16:50:30

%S 1,3,13,121,4959,2771103,151947502947

%N A102897(n) - 1.

%C Same as A102897, but counts nonempty set systems.

%K nonn

%O 0,2

%A _N. J. A. Sloane_, Mar 17 2007