Number of unrooted triangulations of a pentagon with n internal nodes.

A005501

Number of unrooted triangulations of a pentagon with n internal nodes.

Terms

    a(0) =1a(1) =4a(2) =14a(3) =69a(4) =396a(5) =2503a(6) =16905a(7) =119571a(8) =874771a(9) =6567181a(10) =50329363a(11) =392328944a(12) =3102523829a(13) =24839151315a(14) =201011560316

External references