OFFSET
0,4
LINKS
FORMULA
a(n)=[3+(1-2i)(i-1)^n+(1+2i)(-1-i)^n]/5 where i=sqrt(-1). - R. J. Mathar, Apr 25 2008
O.g.f.: -(1+2x)/((1+2x+2x^2)(-1+x)). - R. J. Mathar, Apr 25 2008
a(n+1)-a(n)=A090132(n+1). - R. J. Mathar, Apr 25 2008
G.f.: Q(0)*(1+2*x)/(2- 2*x), where Q(k) = 1 + 1/(1 - x*(4*k+2 +2*x)/(x*(4*k+4 +2*x) - 1/Q(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Jan 01 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Apr 20 2008
EXTENSIONS
More terms from R. J. Mathar, Apr 25 2008
STATUS
approved