Number of n-node simple unicyclic graphs.

Terms

a(0) =1a(1) =3a(2) =9a(3) =25a(4) =68a(5) =185a(6) =504a(7) =1379a(8) =3788a(9) =10480a(10) =29094a(11) =81193a(12) =227379a(13) =639099a(14) =1801394a(15) =5091388a(16) =14422301a(17) =40939337a(18) =116420959a(19) =331622137a(20) =946020596a(21) =2702412657a(22) =7729367873a(23) =22132856218a(24) =63444473053a(25) =182046034559a(26) =522841943138