%I M4428 N1872 #35 Dec 09 2023 12:13:40
%S 7,46,4336,134281216,288230380379570176,
%T 2658455991569831764110243006194384896,
%U 452312848583266388373324160190187140390789016525312000869601987902398529536
%N Number of switching networks (see Harrison reference for precise definition).
%C Number of equivalence classes with complementation of n variables on the domain and symmetric group of 2 variables operating on the range. - _Sean A. Irvine_, Jul 11 2011
%C Essentially the same sequence as A000231. - _Sean A. Irvine_, Jul 11 2011
%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 M. A. Harrison, <a href="https://doi.org/10.1016/0016-0032(63)90456-3">On the number of classes of switching networks</a>, J. Franklin Instit., 276 (1963), 313-327.
%H <a href="/index/Sw#switching">Index entries for sequences related to switching networks</a>
%F a(n) = 2^(2^(n+1) - n - 1) + 2^(2^n) - 2^(2^n - n - 1). - _Sean A. Irvine_, Jul 11 2011 [Corrected by _Sean A. Irvine_, Dec 07 2023]
%t a[n_]:= 2^(2^(n+1) - n - 1) + 2^(2^n) - 2^(2^n - n - 1); Table[a[n], {n, 7}] (* _James C. McMahon_, Dec 09 2023 *)
%K nonn
%O 1,1
%A _N. J. A. Sloane_
%E More terms from _Sean A. Irvine_, Jul 10 2011
%E a(7) corrected by _Sean A. Irvine_, May 29 2013