A341917 Number of strong triangulations of a fixed pentagon with n interior nodes.

1, 10, 80, 610, 4625, 35322, 272800, 2132310, 16861455, 134781350, 1088074064, 8863227100, 72789560025, 602232150810, 5016320750400, 42041168169712, 354326295908580, 3001705818071400, 25549873091193600, 218426240780417250, 1874878554813727815, 16153461053030605590

Offset: 1

Author

Andrew Howroyd, Feb 23 2021

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..500

Crossrefs

Column k=2 of A341856.

Cf. A341853.

Programs

PARI

a(n)={60*(13*n+9)*(4*n+5)!/((3*n+9)!*(n-1)!)}

Formula

a(n) = 60*(13*n+9)*(4*n+5)!/((3*n+9)!*(n-1)!).