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

Terms

a(0) =1a(1) =4a(2) =11a(3) =28a(4) =67a(5) =152a(6) =335a(7) =724a(8) =1539a(9) =3232a(10) =6727a(11) =13900a(12) =28555a(13) =58392a(14) =118959a(15) =241604a(16) =489459a(17) =989520a(18) =1997015a(19) =4024508a(20) =8100699a(21) =16289032a(22) =32726655a(23) =65705268a(24) =131837763a(25) =264399936a(26) =530028199a(27) =1062139180a(28) =2127809963