0,5

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. A046910.

Sequence in context: A112321 A003419 A126109 this_sequence A041879 A011550 A102023

Adjacent sequences: A046906 A046907 A046908 this_sequence A046910 A046911 A046912

nonn

John A. Wright.