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

Terms

a(0) =1a(1) =3a(2) =9a(3) =27a(4) =78a(5) =225a(6) =648a(7) =1863a(8) =5355a(9) =15390a(10) =44226a(11) =127089a(12) =365202a(13) =1049436a(14) =3015630a(15) =8665623a(16) =24901263a(17) =71555481a(18) =205619553a(19) =590861790a(20) =1697881581a(21) =4878978300a(22) =14020076241a(23) =40287643353a(24) =115769285316a(25) =332670921048