Expansion of g.f. (1 + 2*x) / (1 + 2*x + 4*x^2).

Terms

a(0) =1a(1) =0a(2) =-4a(3) =8a(4) =0a(5) =-32a(6) =64a(7) =0a(8) =-256a(9) =512a(10) =0a(11) =-2048a(12) =4096a(13) =0a(14) =-16384a(15) =32768a(16) =0a(17) =-131072a(18) =262144a(19) =0a(20) =-1048576a(21) =2097152a(22) =0a(23) =-8388608a(24) =16777216a(25) =0a(26) =-67108864a(27) =134217728a(28) =0a(29) =-536870912