Expansion of (1+4x-6x^2-36x^3)/(1-19x^2+90x^4).

Terms

a(0) =1a(1) =4a(2) =13a(3) =40a(4) =157a(5) =400a(6) =1813a(7) =4000a(8) =20317a(9) =40000a(10) =222853a(11) =400000a(12) =2405677a(13) =4000000a(14) =25651093a(15) =40000000a(16) =270859837a(17) =400000000a(18) =2837738533a(19) =4000000000a(20) =29539646797a(21) =40000000000a(22) =305856821173a(23) =400000000000