Powers of fourth root of 18 rounded up.

Terms

a(0) =1a(1) =3a(2) =5a(3) =9a(4) =18a(5) =38a(6) =77a(7) =158a(8) =324a(9) =668a(10) =1375a(11) =2832a(12) =5832a(13) =12013a(14) =24744a(15) =50965a(16) =104976a(17) =216227a(18) =445376a(19) =917370a(20) =1889568a(21) =3892071a(22) =8016759a(23) =16512655a(24) =34012224a(25) =70057262a(26) =144301646a(27) =297227789a(28) =612220032