OFFSET
0,2
LINKS
Ivan Panchenko, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
G.f.: x*(-3 + 8*x + 7*x^2)/(1-x)^4. - Ivan Panchenko, Nov 09 2013
From G. C. Greubel, Jul 30 2016: (Start)
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
E.g.f.: x*(-3 + x + 2*x^2)*exp(x). (End)
MATHEMATICA
Table[(2*n - 5)n^2, {n, 0, 25}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {0, -3, -4, 9}, 25] (* G. C. Greubel, Jul 30 2016 *)
PROG
(PARI) a(n)=(2*n-5)*n^2 \\ Charles R Greathouse IV, Jul 30 2016
CROSSREFS
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Dec 11 1999
STATUS
approved