OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n=1,...,1000
M. Azaola and F. Santos, The number of triangulations of the cyclic polytope C(n,n-4), Discrete Comput. Geom., 27 (2002), 29-48.
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1)
FORMULA
G.f.: x*(1-3*x+8*x^2-5*x^3+5*x^4) / (1-x)^5 . - R. J. Mathar, Aug 07 2014
MATHEMATICA
LinearRecurrence[{5, -10, 10, -5, 1}, {1, 2, 8, 25, 65}, 50] (* Vladimir Joseph Stephan Orlovsky, Feb 21 2012 *)
PROG
(PARI) { for (n=1, 1000, a=6*binomial(n, 4) + 5*binomial(n, 2) - 4*n + 5; write("b066455.txt", n, " ", a) ) } \\ Harry J. Smith, Feb 15 2010
(Magma) [6*Binomial(n, 4)+5*Binomial(n, 2)-4*n+5: n in [1..40]]; // Vincenzo Librandi, Aug 07 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 04 2002
STATUS
approved