OFFSET
0,2
COMMENTS
a(0)=1, a(2n-1)=k^(2n-1), a(2n)=(2-k)k^(2n-1), k=4; G.f.: (1+kx+(2-2k)kx^2)/((1-kx)(1+kx)), k=4.
LINKS
FORMULA
a(n)=4^n/4+(-3)(-4)^n/4+6*0^n/4
MATHEMATICA
LinearRecurrence[{0, 16}, {1, 4, -8}, 30] (* Harvey P. Dale, Dec 14 2019 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Dec 19 2003
STATUS
approved