%I M3533 N1433 #20 Apr 01 2017 00:24:21
%S 4,16,392,1966074,800887365826790,1230766671361406290474145896188319,
%T 29914870938046718875870447490073662976109190218710989290080175747776895
%N Number of switching networks with S(n) and C(2,2) acting on the domain and GL(2,2) acting on the range.
%D M. A. Harrison, On the number of classes of switching networks, J. Franklin Instit., 276 (1963), 313-327. (Available on-line at http://deepblue.lib.umich.edu/handle/2027.42/5406/.)
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H <a href="/index/Sw#switching">Index entries for sequences related to switching networks</a>
%K nonn
%O 1,1
%A _N. J. A. Sloane_
%E More terms from _Sean A. Irvine_, Jan 25 2012