OFFSET
4,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 4..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
For n>4, a(n) = a(n-1)+A022856(n+2). - Levi R. Self (levi.r.self(AT)gmail.com), Aug 04 2007
G.f.: -x^4*(7*x^3-24*x^2+28*x-12)/(x-1)^4. - Colin Barker, Oct 07 2012
a(n) = n*(n^2-3*n+14)/6. - Vincenzo Librandi, Oct 17 2013
MATHEMATICA
CoefficientList[Series[-(7 x^3 - 24 x^2 + 28 x - 12)/(x - 1)^4, {x, 0, 60}], x] (* Vincenzo Librandi, Oct 17 2013 *)
PROG
(Magma) [n*(n^2-3*n+14)/6: n in [4..60]]; // Vincenzo Librandi, Oct 17 2013
(PARI) a(n)=n*(n^2-3*n+14)/6 \\ Charles R Greathouse IV, Oct 18 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved