a(n) = 2*a(n-1) + 5*a(n-2), a(0) = 0, a(1) = 1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =9a(4) =28a(5) =101a(6) =342a(7) =1189a(8) =4088a(9) =14121a(10) =48682a(11) =167969a(12) =579348a(13) =1998541a(14) =6893822a(15) =23780349a(16) =82029808a(17) =282961361a(18) =976071762a(19) =3366950329a(20) =11614259468a(21) =40063270581a(22) =138197838502a(23) =476712029909