a(n) = 3*a(n-1) + 5*a(n-2), with a(0)=1, a(1)=1.

Terms

a(0) =1a(1) =1a(2) =8a(3) =29a(4) =127a(5) =526a(6) =2213a(7) =9269a(8) =38872a(9) =162961a(10) =683243a(11) =2864534a(12) =12009817a(13) =50352121a(14) =211105448a(15) =885076949a(16) =3710758087a(17) =15557659006a(18) =65226767453a(19) =273468597389