%I A000664 M1400 N0545
%S A000664 1,1,2,5,11,26,68,177,497,1476,4613,15216,52944,193367,740226,2960520,
%T A000664 12334829,53394755,239544624,1111261697,5320103252,26237509076,
%U A000664 133087001869,693339241737,3705135967663,20286965943329,113694201046379
%N A000664 Number of graphs with n edges.
%C A000664 These are simple graphs, unlabeled, with no isolated nodes, but are not 
               necessarily connected.
%D A000664 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000664 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000664 W. Oberschelp, Kombinatorische Anzahlbestimmungen in Relationen, Math. 
               Ann., 174 (1967), 53-78.
%D A000664 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 
               146.
%D A000664 M. L. Stein and P. R. Stein, Enumeration of Linear Graphs and Connected 
               Linear Graphs up to $p = 18$ Points. Report LA-3775, Los Alamos Scientific 
               Laboratory of the University of California, Los Alamos, NM, Oct 1967.
%H A000664 P. J. Cameron, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">
               Sequences realized by oligomorphic permutation groups</a>, J. Integ. 
               Seqs. Vol. 3 (2000), #00.1.5.
%F A000664 Euler transform of A002905 (ignoring A002905(0)). - Franklin T. Adams-Watters 
               (FrankTAW(AT)Netscape.net) Jul 03 2009
%e A000664 n=1: o-o (1)
%e A000664 n=2: o-o o-o, o-o-o (2)
%e A000664 n=3: o-o o-o o-o, o-o-o o-o, o-o-o-o, Y, triangle (5)
%e A000664 n=4: o-o o-o o-o o-o, o-o-o o-o o-o, o-o-o o-o-o, o-o o-o-o-o, o-o Y, 
               o-o triangle,
%e A000664 o-o-o-o-o, >o-o-o, ><, square, triangle with tail (11)
%Y A000664 Cf. A008406.
%Y A000664 Sequence in context: A025245 A079223 A095892 this_sequence A067922 A095975 
               A006652
%Y A000664 Adjacent sequences: A000661 A000662 A000663 this_sequence A000665 A000666 
               A000667
%K A000664 nonn,nice
%O A000664 0,3
%A A000664 N. J. A. Sloane (njas(AT)research.att.com).
%E A000664 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 08 2000, Aug 
               14 2007
%E A000664 Edited by N. J. A. Sloane (njas(AT)research.att.com), Feb 26 2008
%E A000664 Example for n=2 corrected by Adrian Falcone (falcone(AT)gmail.com), Jan 
               28 2009
%E A000664 Zero term inserted by Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), 
               Jul 03 2009
%E A000664 a(25)-a(26) from Max Alekseyev (maxale(AT)gmail.com), Sep 19 2009