Expansion of (1-2*x-3*x^2)/((1-2*x)*(1-4*x)).

Terms

a(0) =1a(1) =4a(2) =13a(3) =46a(4) =172a(5) =664a(6) =2608a(7) =10336a(8) =41152a(9) =164224a(10) =656128a(11) =2622976a(12) =10488832a(13) =41949184a(14) =167784448a(15) =671113216a(16) =2684403712a(17) =10737516544a(18) =42949869568a(19) =171799085056a(20) =687195553792