A000884 Number of switching networks with C(2,n) acting on the domain and AG(3,2) acting on the domain. (Formerly M1994 N0786)

2, 10, 2104, 13098898366, 1842172695541070949024622, 72975978136470898183217648961745628914523492408810350

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) = (224*2^(2^n) + 42*4^(2^n) + 8^(2^n) + 448*2^(n + 2^(n-1)) + 92*2^(n + 2^n + 2^(n-1)) + 384*2^n + 168*2^(n+2^n) - 448*2^(2^(n-1)) - 92*2^(2^n + 2^(n-1)))/(1344*2^n). - Sean A. Irvine, Jan 24 2012

Mathematica

Table[(224*2^(2^n)+42*4^(2^n)+8^(2^n)+448*2^(n+2^(n-1))+92*2^(n+2^n+2^(n-1))+384*2^n+168*2^(n+2^n)-448*2^(2^(n-1))-92*2^(2^n+2^(n-1)))/(1344*2^n), {n, 1, 11}] (* Vincenzo Librandi, Mar 28 2012 *)

Crossrefs

Sequence in context: A057015 A059732 A334575 * A328157 A013557 A007158

Adjacent sequences: A000881 A000882 A000883 * A000885 A000886 A000887

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Jan 23 2012

Status

approved