%I M3658 #14 Dec 18 2021 20:40:20
%S 1,1,4,35,541,13062,444767,19912657,1121041222,77048430033,
%T 6329916102841,611728117464928,68657066350744197,8854866422322096893,
%U 1300613343254300891316
%N Number of connected labeled interval graphs with n nodes.
%D P. J. Hanlon, personal communication.
%D R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1980.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H R. W. Robinson, <a href="/A005973/b005973.txt">Table of n, a(n) for n = 1..30</a>
%H Phil Hanlon, <a href="http://dx.doi.org/10.1090/S0002-9947-1982-0662044-8">Counting interval graphs</a>, Trans. Amer. Math. Soc. 272 (1982), no. 2, 383-426.
%K nonn,nice
%O 1,3
%A _N. J. A. Sloane_