A003097 Critical connected topologies with n points. (Formerly M2677)

1, 3, 7, 20, 52, 157, 458, 1436, 4531, 14794, 48944, 165314

Offset

2,2

References

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=2..13.

S. K. Das, On the enumeration of finite maximal connected topologies, J. Combin. Theory, B 15 (1973), 184-199.

Crossrefs

Sequence in context: A066315 A339061 A058499 * A109220 A293734 A018034

Adjacent sequences: A003094 A003095 A003096 * A003098 A003099 A003100

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

a(8)-a(13) from Sean A. Irvine, Feb 01 2015

Status

approved