A000854 - OEIS

%I M3687 N1506 #34 Jan 17 2025 12:09:40

%S 4,51,46218,366543984720,51580835042395388382652416,

%T 2043327387821185145142410066588796212566159639921557504

%N Number of n-input 3-output switching networks under action of complementing group C(2,n) on inputs and S(3) and C(2,3) on outputs.

%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 Vincenzo Librandi, <a href="/A000854/b000854.txt">Table of n, a(n) for n = 1..10</a>

%H <a href="/index/Sw#switching">Index entries for sequences related to switching networks</a>

%F a(n) = (1/48)*(8^(2^n) + 20*(2^n-1)*8^(2^(n-1)) + 8*2^(2^n) + 16*(2^n-1)*2^(2^(n-1)) + 6*4^(2^n))/(2^n). - _Sean A. Irvine_, Aug 11 2011

%o (Magma) [1/48*(8^(2^n)+20*(2^n-1)*8^(2^(n-1))+8*2^(2^n)+16*(2^n-1)*2^(2^(n-1))+6*4^(2^n))/(2^n): n in [1..12]]; // _Vincenzo Librandi_, Aug 11 2011

%K nonn

%O 1,1

%A _N. J. A. Sloane_

%E More terms from _Sean A. Irvine_, Aug 10 2011