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 A000868 Number of switching networks with C(2,n) acting on domain and GL(2,Z2) acting on range. (Formerly M3580 N1451) 1
 4, 21, 1531, 44782251, 96076794891512491, 886151997189943927518995693301312171, 150770949527755462791108053396729046910357127815416821444325531778055580331 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Next term has 151 digits. - Sean A. Irvine, Jan 23 2012 REFERENCES M. A. Harrison, On the number of classes of switching networks, J. Franklin Instit., 276 (1963), 313-327. N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..10 Index entries for sequences related to switching networks FORMULA a(n) = (2^(2^(n+1)) + 2^(n+2 + 2^n) - 2^(2^n) + 2^(n+1))/(3*2^(n+1)). - Sean A. Irvine, Jan 23 2012 CROSSREFS Sequence in context: A118909 A225157 A158947 * A000875 A094046 A326603 Adjacent sequences: A000865 A000866 A000867 * A000869 A000870 A000871 KEYWORD nonn AUTHOR N. J. A. Sloane EXTENSIONS More terms from Sean A. Irvine, Jan 22 2012 STATUS approved

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Last modified December 4 01:01 EST 2023. Contains 367541 sequences. (Running on oeis4.)