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Number of Q-graphs with 2n edges.
(Formerly M1877)
1

%I M1877 #16 Nov 08 2017 02:25:16

%S 0,1,2,8,48,328,2335,17133,128262,975547,7518282,58582564,460769228,

%T 3653385453,29170737927,234350263419,1892956305974,15364355580327,

%U 125247311808502,1024983176867450,8417817643684208,69355110426227296

%N Number of Q-graphs with 2n edges.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H R. C. Read, <a href="http://dx.doi.org/10.1007/BF02188172">On the enumeration of a class of plane multigraphs</a>, Aequat. Math. 31 (1986) no 1, 47-63.

%F a(n) = A007169(n) + (A294724(n) - A294728(n)) / 2. - _Sean A. Irvine_, Nov 07 2017

%Y Cf. A007169, A294724, A294728.

%K nonn

%O 1,3

%A _N. J. A. Sloane_.

%E a(9) corrected and more terms from _Sean A. Irvine_, Nov 07 2017