OFFSET
0,7
COMMENTS
Absolute values appear to be given (with the same offset) by A103221. - Jason Kimberley, Oct 17 2011
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,1,-1,0,1).
FORMULA
Conjectured g.f.: 1/( (1-x)*(1-x+x^2)*(1+x)^2 ) with a(n) = +a(n-2) -a(n-3) +a(n-5). - R. J. Mathar, Jun 30 2011
The above conjecture is correct. - Charles R Greathouse IV, Dec 28 2011
PROG
(PARI) a(n)=(-1)^n*(n\2-(n-1)\3) \\ Charles R Greathouse IV, Dec 28 2011
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Barry, Mar 08 2011
STATUS
approved