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

Terms

a(0) =1a(1) =4a(2) =16a(3) =62a(4) =239a(5) =920a(6) =3540a(7) =13620a(8) =52401a(9) =201604a(10) =775636a(11) =2984122a(12) =11480879a(13) =44170640a(14) =169938680a(15) =653808840a(16) =2515413201a(17) =9677604804a(18) =37232862856a(19) =143246816182a(20) =551116641919