a(n) = floor((5^n+1)/(2*3^n)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =10a(6) =17a(7) =29a(8) =49a(9) =82a(10) =137a(11) =229a(12) =382a(13) =638a(14) =1063a(15) =1772a(16) =2953a(17) =4923a(18) =8205a(19) =13675a(20) =22792a(21) =37987a(22) =63312a(23) =105521a(24) =175868a(25) =293114a(26) =488524a(27) =814207a(28) =1357012a(29) =2261686