%I #3 Mar 30 2012 18:36:57
%S 1,1,-1,1,1,-1,3,-3,1,7,-13,13,1,-25,51,-51,1,103,-205,205,1,-409,819,
%T -819,1,1639,-3277,3277,1,-6553,13107,-13107,1,26215,-52429,52429,1,
%U -104857,209715,-209715,1,419431,-838861,838861,1,-1677721,3355443,-3355443,1,6710887,-13421773,13421773,1
%N Row sums of triangle A118407.
%F G.f.: (1+x)^2/(1+x^2)/(1+2*x+2*x^2)/(1-x).
%o (PARI) {a(n)=polcoeff((1+x)^2/(1+x^2)/(1+2*x+2*x^2)/(1-x+x*O(x^n)),n)}
%Y Cf. A118407 (triangle), A118409 (unsigned row sums).
%K sign
%O 0,7
%A _Paul D. Hanna_, Apr 27 2006