OFFSET
0,3
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
From Colin Barker, Aug 04 2019: (Start)
G.f.: -x*(1 - 6*x) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2.
(End)
MAPLE
a := n -> (1/2)*n*(5*n - 7): seq(a(n), n=0..48);
PROG
(PARI) concat(0, Vec(-x*(1 - 6*x) / (1 - x)^3 + O(x^40))) \\ Colin Barker, Aug 04 2019
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Peter Luschny, Aug 04 2019
STATUS
approved