Number of unlabeled 2,3 cacti (triangular cacti with bridges) rooted at a triangle with n triangles and every node contained in exactly one triangle.
A381469
Number of unlabeled 2,3 cacti (triangular cacti with bridges) rooted at a triangle with n triangles and every node contained in exactly one triangle.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =4a(4) =15a(5) =66a(6) =304a(7) =1503a(8) =7622a(9) =39856a(10) =212447a(11) =1151614a(12) =6324924a(13) =35127396a(14) =196917025a(15) =1112776860a(16) =6332114208a(17) =36252066562a(18) =208665030299
External references
- oeis: A381469