%I A005975 M1224
%S A005975 1,2,4,10,27,92,369,1807,10344,67659,491347,3894446,33278992,304256984,
%T A005975 2960093835,30523315419,332524557107,3816805831381,46048851321131,582691924941142,
%U A005975 7717878059859874,106806430860694984,1541683193805924288,23173865491070682522
%N A005975 Number of interval graphs on n unlabeled nodes.
%D A005975 Hanlon, Phil; Counting interval graphs. Trans. Amer. Math. Soc. 272 (1982), 
               no. 2, 383-426.
%D A005975 P. J. Hanlon, personal communication.
%D A005975 R. W. Robinson, Numerical implementation of graph counting algorithms, 
               AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1980.
%D A005975 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A005975 R. W. Robinson, <a href="b005975.txt">Table of n, a(n) for n = 1..30</
               a>
%Y A005975 Sequence in context: A057786 A007776 A123428 this_sequence A048193 A123411 
               A128933
%Y A005975 Adjacent sequences: A005972 A005973 A005974 this_sequence A005976 A005977 
               A005978
%K A005975 nonn
%O A005975 1,2
%A A005975 N. J. A. Sloane (njas(AT)research.att.com).
%E A005975 a(21) onwards added by N. J. A. Sloane (njas(AT)research.att.com), Oct 
               19 2006 from the Robinson reference