0,3

J. A. Wright, There are 718 6-point topologies, quasi-orderings, and transgraphs, Notices Amer. Math. Soc., 17 (1970), p. 646, Abstract #70T-A106.

Cf. A046912.

Sequence in context: A027740 A132880 A019537 this_sequence A089127 A132852 A055790

Adjacent sequences: A046908 A046909 A046910 this_sequence A046912 A046913 A046914

nonn,nice

John A. Wright.