%I M5093 N2205 #20 Feb 12 2015 08:18:12
%S 20,220,23932,2390065448,1320590620757744871288,
%T 51897350327827018479313921072100496772300552736
%N Number of switching networks (see Harrison reference for precise definition).
%C Next term has 101 digits. - _Sean A. Irvine_, Jan 20 2012
%C Number of equivalence classes with GL_n(Z_2) operating on the domain and symmetric group of 3 variables operating on the range. - _Sean A. Irvine_, Jan 20 2012
%D M. A. Harrison, On the number of classes of switching networks, J. Franklin Instit., 276 (1963), 313-327.
%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 19 2012