Number of unlabeled simple graphs covering n vertices with a unique undirected cycle of length > 2.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =6a(6) =16a(7) =43a(8) =117a(9) =319a(10) =875a(11) =2409a(12) =6692a(13) =18614a(14) =52099a(15) =146186a(16) =411720a(17) =1162295a(18) =3289994a(19) =9330913a(20) =26517036a(21) =75481622a(22) =215201178a(23) =614398459a(24) =1756392061a(25) =5026955216a(26) =14403488345a(27) =41311616835a(28) =118601561506a(29) =340795908579