A000808 Number of switching networks (see Harrison reference for precise definition). (Formerly M4726 N2020)

10, 76, 8416, 268496896, 576460756464173056, 5316911983139663509773741938679218176, 904625697166532776746648320380374280441295666129685538275829368373028847616

Offset

1,1

Comments

The next term a(8) 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..12

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

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 49

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 51

Index entries for sequences related to switching networks

Formula

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

Mathematica

a[n_]:=(2^(2^(n+1))+(2^n-1)*2^(2^n))/2^n; Table[a[n], {n, 7}] (* James C. McMahon, Dec 07 2023 *)

Prog

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

Crossrefs

Cf. A000079, A001146.

Sequence in context: A184273 A185986 A225828 * A159579 A244720 A081678

Adjacent sequences: A000805 A000806 A000807 * A000809 A000810 A000811

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Jul 03 2011

Status

approved