OFFSET
0,2
LINKS
J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.
Index entries for linear recurrences with constant coefficients, signature (-1,1,1).
FORMULA
O.g.f.: (1+3x+4x^2)/((1-x)(1+x)^2). a(n)=2+(n-1)*(-1)^n. [From R. J. Mathar, Aug 22 2008]
EXAMPLE
a(4)=0 because 1+2-3=0
MATHEMATICA
LinearRecurrence[{-1, 1, 1}, {1, 2, 3}, 80] (* Harvey P. Dale, Jul 15 2023 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Gregory V. Richardson, Oct 17 2000
EXTENSIONS
More terms from James A. Sellers, Oct 18 2000
STATUS
approved