a(n) = floor(8^n/5^n).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =10a(6) =16a(7) =26a(8) =42a(9) =68a(10) =109a(11) =175a(12) =281a(13) =450a(14) =720a(15) =1152a(16) =1844a(17) =2951a(18) =4722a(19) =7555a(20) =12089a(21) =19342a(22) =30948a(23) =49517a(24) =79228a(25) =126765a(26) =202824a(27) =324518a(28) =519229a(29) =830767