Powers of fourth root of 21 rounded down.

Terms

a(0) =1a(1) =2a(2) =4a(3) =9a(4) =21a(5) =44a(6) =96a(7) =206a(8) =441a(9) =944a(10) =2020a(11) =4326a(12) =9261a(13) =19824a(14) =42439a(15) =90849a(16) =194481a(17) =416324a(18) =891223a(19) =1907838a(20) =4084101a(21) =8742815a(22) =18715701a(23) =40064612a(24) =85766121a(25) =183599118a(26) =393029741a(27) =841356858a(28) =1801088541a(29) =3855581491