A000833 Number of switching networks (see Harrison reference for precise definition). (Formerly M5093 N2205)

20, 220, 23932, 2390065448, 1320590620757744871288, 51897350327827018479313921072100496772300552736

Offset

1,1

Comments

Next term has 101 digits. - Sean A. Irvine, Jan 20 2012

Number of equivalence classes with GL_n(Z_2) operating on the domain and symmetric group of 3 variables operating on the range. - Sean A. Irvine, Jan 20 2012

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

Table of n, a(n) for n=1..6.

Index entries for sequences related to switching networks

Crossrefs

Sequence in context: A004411 A140354 A155673 * A302661 A178261 A054329

Adjacent sequences: A000830 A000831 A000832 * A000834 A000835 A000836

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Jan 19 2012

Status

approved