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

Terms

a(0) =1a(1) =5a(2) =8a(3) =23a(4) =47a(5) =116a(6) =257a(7) =605a(8) =1376a(9) =3191a(10) =7319a(11) =16892a(12) =38849a(13) =89525a(14) =206072a(15) =474647a(16) =1092863a(17) =2516804a(18) =5795393a(19) =13345805a(20) =30731984a(21) =70769399a(22) =162965351a(23) =375273548a(24) =864169601a(25) =1989990245a(26) =4582499048a(27) =10552469783a(28) =24299966927