Expansion of x/(1 - 2*x^2 - 21*x^3).

Terms

a(0) =0a(1) =1a(2) =0a(3) =2a(4) =21a(5) =4a(6) =84a(7) =449a(8) =252a(9) =2662a(10) =9933a(11) =10616a(12) =75768a(13) =229825a(14) =374472a(15) =2050778a(16) =5575269a(17) =11965468a(18) =54216876a(19) =141011585a(20) =359708580a(21) =1420577566a(22) =3680660445a(23) =10395035312a(24) =37193449776a(25) =98083939969a(26) =292682641104a(27) =977230325234