Number of unrooted triangulations of a disk that have reflection symmetry with n interior nodes and 3 nodes on the boundary.

A002712

Number of unrooted triangulations of a disk that have reflection symmetry with n interior nodes and 3 nodes on the boundary.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =8a(5) =23a(6) =68a(7) =215a(8) =680a(9) =2226a(10) =7327a(11) =24607a(12) =83060a(13) =284046a(14) =975950a(15) =3383343a(16) =11778308a(17) =41269252a(18) =145131502a(19) =512881550a(20) =1818259952a(21) =6470758289a(22) =23091680690a(23) =82659905947a(24) =296605398856

External references