OFFSET
0,5
COMMENTS
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,-1).
FORMULA
a(0) = a(2)=0, a(1)=a(3)=-1, a(4)=2.
a(n) = a(n-4) + 2, n > 3.
a(n) = a(n-1) + a(n-4) - a(n-5), n > 4.
A214297(n) = a(n+1) * d(n+1).
G.f.: x*(3*x^3-x^2+x-1) / ((x-1)^2*(x+1)*(x^2+1)). - Colin Barker, Sep 22 2013
MATHEMATICA
Table[{0, -1} + 2*Floor[n/2], {n, 0, 31}] // Flatten (* Jean-François Alcover, Jun 03 2013 *)
PROG
(PARI) a(n)=n\4*2-n%2 \\ Charles R Greathouse IV, Sep 15 2013
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Jun 02 2013
STATUS
approved