OFFSET
3,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 3..1000
J. A. De Loera, F. Santos and F. Takeuchi, Extremal properties of optimal dissections of convex polytopes, SIAM Journal Discrete Mathematics, 14, 2001, 143-161.
M. Develin, Maximal triangulations of a regular prism
Index entries for linear recurrences with constant coefficients, signature (2,0,-2,1).
FORMULA
a(n) = floor((n^2 + 8n - 16)/4). - Ralf Stephan, Oct 13 2003
a(n) = (-33+(-1)^n+16*n+2*n^2)/8. a(n) = 2*a(n-1)-2*a(n-3)+a(n-4). G.f.: -x^3*(x^3-4*x^2+4) / ((x-1)^3*(x+1)). - Colin Barker, Sep 06 2013
MATHEMATICA
CoefficientList[Series[-(x^3 - 4 x^2 + 4)/((x - 1)^3 (x + 1)), {x, 0, 60}], x] (* Vincenzo Librandi, Oct 21 2013 *)
LinearRecurrence[{2, 0, -2, 1}, {4, 8, 12, 17}, 60] (* Harvey P. Dale, Nov 28 2014 *)
PROG
(PARI) Vec(-x^3*(x^3-4*x^2+4)/((x-1)^3*(x+1)) + O(x^100)) \\ Colin Barker, Sep 06 2013
(Magma) [Floor((n^2+8*n-16)/4): n in [3..60]]; // Vincenzo Librandi, Oct 21 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jesus De Loera (deloera(AT)math.ucdavis.edu)
EXTENSIONS
More terms from Ralf Stephan, Oct 13 2003
STATUS
approved