Expansion of Product_{k>0} (-1+sqrt(1+4*x^k))/(2*x^k).

Terms

a(0) =1a(1) =-1a(2) =1a(3) =-5a(4) =14a(5) =-40a(6) =122a(7) =-404a(8) =1362a(9) =-4608a(10) =15881a(11) =-55709a(12) =197402a(13) =-705114a(14) =2539282a(15) =-9210196a(16) =33605471a(17) =-123262137a(18) =454268676a(19) =-1681305246a(20) =6246544735a(21) =-23288217459a(22) =87096982499a(23) =-326680267261