Expansion of (1+x)/sqrt(1+4x^2).

Terms

a(0) =1a(1) =1a(2) =-2a(3) =-2a(4) =6a(5) =6a(6) =-20a(7) =-20a(8) =70a(9) =70a(10) =-252a(11) =-252a(12) =924a(13) =924a(14) =-3432a(15) =-3432a(16) =12870a(17) =12870a(18) =-48620a(19) =-48620a(20) =184756a(21) =184756a(22) =-705432a(23) =-705432a(24) =2704156a(25) =2704156a(26) =-10400600a(27) =-10400600a(28) =40116600a(29) =40116600