%I M2677 #17 Oct 20 2023 22:40:16
%S 1,3,7,20,52,157,458,1436,4531,14794,48944,165314
%N Critical connected topologies with n points.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H S. K. Das, <a href="http://dx.doi.org/10.1016/0095-8956(73)90020-8">On the enumeration of finite maximal connected topologies</a>, J. Combin. Theory, B 15 (1973), 184-199.
%K nonn,more
%O 2,2
%A _N. J. A. Sloane_
%E a(8)-a(13) from _Sean A. Irvine_, Feb 01 2015