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A341917
Number of strong triangulations of a fixed pentagon with n interior nodes.
3
1, 10, 80, 610, 4625, 35322, 272800, 2132310, 16861455, 134781350, 1088074064, 8863227100, 72789560025, 602232150810, 5016320750400, 42041168169712, 354326295908580, 3001705818071400, 25549873091193600, 218426240780417250, 1874878554813727815, 16153461053030605590
OFFSET
1,2
LINKS
FORMULA
a(n) = 60*(13*n+9)*(4*n+5)!/((3*n+9)!*(n-1)!).
PROG
(PARI) a(n)={60*(13*n+9)*(4*n+5)!/((3*n+9)!*(n-1)!)}
CROSSREFS
Column k=2 of A341856.
Cf. A341853.
Sequence in context: A257286 A125373 A093145 * A369474 A037509 A037692
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Feb 23 2021
STATUS
approved