%I #10 Jun 26 2022 19:49:26
%S 1,1,3,7,20,55,162,477,1450,4446,13858,43589,138515,443487,1430261,
%T 4640312,15137893,49620637,163360133,539904503,1790699059,5958280016,
%U 19883532941,66532519727,223177199775,750340752081,2528058240115
%N Main diagonal of A058735.
%C Also the number of unlabeled cographs on n nodes with two components. - _Vladeta Jovovic_, May 07 2005
%D J. Riordan, The blossoming of Schroeder's fourth problem, Acta Math., 137 (1976), 1-16.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Cograph.html">Cograph</a>
%H <a href="/index/Ro#rooted">Index entries for sequences related to rooted trees</a>
%F G.f.: A(x) = (B(x)^2 + B(x^2))/2, where B(x) = g.f. for A000669. - _Vladeta Jovovic_, May 07 2005
%Y Cf. A000669, A058735, A106240.
%K nonn
%O 2,3
%A _N. J. A. Sloane_, Jan 01 2001
%E More terms from _Vladeta Jovovic_, May 07 2005