Expansion of (1+2*x-x^2) / (1-2*x-5*x^2+2*x^3).

Terms

a(0) =1a(1) =4a(2) =12a(3) =42a(4) =136a(5) =458a(6) =1512a(7) =5042a(8) =16728a(9) =55642a(10) =184840a(11) =614434a(12) =2041784a(13) =6786058a(14) =22552168a(15) =74951058a(16) =249090840a(17) =827832634a(18) =2751217352a(19) =9143416194a(20) =30387253880a(21) =100989154026a(22) =335627745064