Number n-cyclic graphs.

Terms

a(0) =1a(1) =3a(2) =3a(3) =10a(4) =12a(5) =35a(6) =58a(7) =160a(8) =341a(9) =958a(10) =2444a(11) =7242a(12) =21190a(13) =67217a(14) =217335a(15) =740542a(16) =2593802a(17) =9444080a(18) =35383843