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,-3,1,0,0,0,0,0,0,0,0,0,0,0,0,1,-3,3,-1).
FORMULA
From R. J. Mathar, Apr 15 2010: (Start)
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-16) - 3*a(n-17) + 3*a(n-18) - a(n-19).
G.f.: x^4*(1+x^2+2*x^6-2*x^7+3*x^8-x^9+x^11+x^12-x^13+x^14) / ( (1-x)^4*(1+x)*(1+x^2)*(1+x^4)*(1+x^8) ). (End)
MATHEMATICA
Table[Floor[(n(n-1)(n-2))/16], {n, 0, 50}] (* Harvey P. Dale, May 16 2012 *)
PROG
(Magma) [Floor(n*(n-1)*(n-2)/16): n in [0..50]]; // Vincenzo Librandi, May 21 2012
(PARI) a(n) = n*(n-1)*(n-2)\16; \\ Michel Marcus, Jan 14 2018
(SageMath) [3*binomial(n, 3)//8 for n in range(51)] # G. C. Greubel, Oct 16 2024
CROSSREFS
KEYWORD
nonn,easy,changed
AUTHOR
STATUS
approved