OFFSET
0,13
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 1, 1).
FORMULA
a(n+4) = A000931(n).
G.f.: ( 1-2*x^2 ) / ( -1+x^2+x^3 ). - R. J. Mathar, Sep 11 2011
a(n) = a(n-2) + a(n-3) with a(0) = -1, a(1) = 0, a(2) = 1. - Taras Goy, Mar 24 2019
MATHEMATICA
LinearRecurrence[{0, 1, 1}, {-1, 0, 1}, 60] (* Harvey P. Dale, Dec 14 2013 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Omar E. Pol, Nov 05 2007
STATUS
approved