Powers of cube root of 9 rounded up.

Terms

a(0) =1a(1) =3a(2) =5a(3) =9a(4) =19a(5) =39a(6) =81a(7) =169a(8) =351a(9) =729a(10) =1517a(11) =3155a(12) =6561a(13) =13648a(14) =28388a(15) =59049a(16) =122827a(17) =255491a(18) =531441a(19) =1105442a(20) =2299412a(21) =4782969a(22) =9948977a(23) =20694705a(24) =43046721a(25) =89540788a(26) =186252345a(27) =387420489a(28) =805867092a(29) =1676271102