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. A046909.

Sequence in context: A042203 A042200 A104593 this_sequence A138246 A125826 A033981

Adjacent sequences: A046907 A046908 A046909 this_sequence A046911 A046912 A046913

nonn

John A. Wright.