Number of unlabeled heptagonal 2-trees with n heptagons.
A094651
Number of unlabeled heptagonal 2-trees with n heptagons.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =4a(4) =20a(5) =158a(6) =1539a(7) =16970a(8) =199879a(9) =2460350a(10) =31266165a(11) =407461893a(12) =5420228329a(13) =73352481577
External references
- oeis: A094651