Number of unrooted triangulations of a disk with 2 internal nodes and n+3 nodes on the boundary.

A005504

Number of unrooted triangulations of a disk with 2 internal nodes and n+3 nodes on the boundary.

Terms

    a(0) =1a(1) =5a(2) =14a(3) =53a(4) =178a(5) =685a(6) =2548a(7) =9876a(8) =37950a(9) =147520a(10) =572594a(11) =2230735a(12) =8693932a(13) =33939465a(14) =132598484a(15) =518607032a(16) =2029990774a(17) =7952788446a(18) =31179668572a(19) =122331725930a(20) =480283816348

External references