Coefficient of x in the reduction of the n-th Fibonacci polynomial by x^3->x^2+2x+1.

Terms

a(0) =0a(1) =1a(2) =0a(3) =4a(4) =3a(5) =18a(6) =30a(7) =98a(8) =219a(9) =596a(10) =1464a(11) =3783a(12) =9540a(13) =24328a(14) =61740a(15) =156985a(16) =398904a(17) =1013772a(18) =2576475a(19) =6547574a(20) =16640382a(21) =42288806a(22) =107473443a(23) =273129468a(24) =694130016a(25) =1764047839a(26) =4483130424a(27) =11393354512a(28) =28954911624a(29) =73585574049