A000854 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 (Formerly M3687 N1506)

4, 51, 46218, 366543984720, 51580835042395388382652416, 2043327387821185145142410066588796212566159639921557504

Offset

1,1

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) = 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

Prog

(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

Crossrefs

Sequence in context: A289708 A000516 A182044 * A232517 A329009 A110908

Adjacent sequences: A000851 A000852 A000853 * A000855 A000856 A000857

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Aug 10 2011

Status

approved