A294728 - OEIS

%I #10 Nov 08 2017 02:26:35

%S 0,0,0,1,1,6,7,37,47,242,324,1658,2300,11764,16741,85741,124383,

%T 638250,939880,4832446,7202214,37101556,55842670,288180066,437325262,

%U 2260516372,3454370352,17881862308,27489383818,142491830992,220185726817

%N Number of Q graphs with 2*n vertices symmetrical about a distinguished edge.

%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 G.f.: H(x) * (B(x^2) - x^2) where H(x) is the g.f. for A007165 and B(x) is the g.f. for A003168.

%Y Cf. A003168, A007165.

%K nonn

%O 1,6

%A _Sean A. Irvine_, Nov 07 2017