OFFSET
0,6
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,-3,3,-1).
FORMULA
a(n) = floor(A007531(n)/28). - Wesley Ivan Hurt, Feb 25 2014
G.f.: x^5*(2-2*x+x^2+x^3-x^4+2*x^6-x^7+x^9-x^10+2*x^11-2*x^12+2*x^13+x^19+ x^21-2*x^22+3*x^23-2*x^24+x^25)/((1-x)^4*(1+x)*(1+x^2)*(1-x+x^2-x^3+x^4-x^5+x^6)*(1+x+x^2+x^3+x^4+x^5+x^6)*(1-x^2+x^4-x^6+x^8-x^10+x^12)). - Peter J. C. Moses, Jun 02 2014
MAPLE
MATHEMATICA
Table[Floor[(n(n-1)(n-2))/28], {n, 0, 80}] (* Harvey P. Dale, Sep 13 2011 *)
PROG
(Magma) [Floor((n*(n-1)*(n-2))/28): n in [0..80]]; // Vincenzo Librandi, Feb 27 2014
(SageMath) [3*binomial(n, 3)//14 for n in range(81)] # G. C. Greubel, Oct 19 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved