Number of Q-graphs with 2n edges.

Terms

a(0) =1a(1) =2a(2) =4a(3) =16a(4) =89a(5) =579a(6) =3989a(7) =28630a(8) =210865a(9) =1584308a(10) =12091902a(11) =93483120a(12) =730503054a(13) =5760438853a(14) =45780146521a(15) =366304396662