A000809 Number of switching networks (see Harrison reference for precise definition). (Formerly M5258 N2290)

36, 1072, 2100736, 17592201773056, 2475880078571033228681936896, 98079714615416886934934209815610010226578261138395365376

Offset

1,1

Comments

The next term a(7) is too large to be displayed here.

References

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..9 (shortened by N. J. A. Sloane, Jan 13 2019)

M. A. Harrison, On the number of classes of switching networks, J. Franklin Instit., 276 (1963), 313-327.

Index entries for sequences related to switching networks

Formula

a(n) = (2^(3*2^n)+(2^n-1)*2^(3*2^(n-1)))/2^n. - Sean A. Irvine, Jul 04 2011

Mathematica

a[n_]:=(2^(3*2^n)+(2^n-1)*2^(3*2^(n-1)))/2^n; Table[a[n], {n, 6}] (* James C. McMahon, Dec 07 2023 *)

Prog

(Magma) [(2^(3*2^n)+(2^n-1)*2^(3*2^(n-1)))/2^n: n in [1..8]]; // Vincenzo Librandi, Jul 04 2011

Crossrefs

Sequence in context: A223358 A184292 A225830 * A151584 A233085 A215858

Adjacent sequences: A000806 A000807 A000808 * A000810 A000811 A000812

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Jul 03 2011

Status

approved