OFFSET
0,6
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4, -6, 3, 3, -6, 3, 3, -6, 4, -1).
FORMULA
G.f.: x^4*(1-x+x^2)*(1-x^2+x^3)/((1-x)^3*(1-x^9)). - Ralf Stephan, Mar 05 2004
From R. J. Mathar, Apr 15 2010: (Start)
a(n) = 4*a(n-1) - 6*a(n-2) + 3*a(n-3) + 3*a(n-4) - 6*a(n-5) + 3*a(n-6) + 3*a(n-7) - 6*a(n-8) + 4*a(n-9) - a(n-10).
G.f.: x^4*(x^2-x+1)*(x^3-x^2+1) / ( (-1+x)^4*(x^6+x^3+1) ). (End)
a(n) = (1/54) * ( n^3 - 3*n - 6 + [6,8,4,-12,8,4,-30,8,4](mod 9) ). - Ralf Stephan, Aug 11 2013
MAPLE
seq(floor(binomial(n, 3)/3), n=0..42); # Zerinvary Lajos, Jan 12 2009
MATHEMATICA
CoefficientList[Series[x^4*(x^2-x+1)*(x^3-x^2+1)/((-1+x)^4*(x^6+x^3+1)), {x, 0, 50}], x] (* Vincenzo Librandi, Jun 19 2012 *)
PROG
(Magma) [Floor(Binomial(n, 3)/3): n in [0..50]]; // Vincenzo Librandi, Jun 19 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved