Number of unlabeled hexagonal 2-trees with n hexagons.

A094637

Number of unlabeled hexagonal 2-trees with n hexagons.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =4a(4) =16a(5) =103a(6) =799a(7) =7286a(8) =71094a(9) =729974a(10) =7743818a(11) =84307887a(12) =937002302a(13) =10595117272a(14) =121568251909

External references