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

Terms

a(0) =1a(1) =4a(2) =14a(3) =52a(4) =203a(5) =808a(6) =3232a(7) =12936a(8) =51765a(9) =207100a(10) =828466a(11) =3313964a(12) =13255999a(13) =53024192a(14) =212097028a(15) =848388448a(16) =3393554217a(17) =13574217396a(18) =54296870230a(19) =217187481700a(20) =868749927731