a(n) = floor(6^n/(2+sqrt(5))^n).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =5a(6) =8a(7) =11a(8) =16a(9) =22a(10) =32a(11) =46a(12) =65a(13) =92a(14) =130a(15) =185a(16) =262a(17) =371a(18) =526a(19) =745a(20) =1056a(21) =1496a(22) =2119a(23) =3001a(24) =4251a(25) =6021a(26) =8528a(27) =12080a(28) =17110a(29) =24236