Powers of cube root of 9 rounded down.

Terms

a(0) =1a(1) =2a(2) =4a(3) =9a(4) =18a(5) =38a(6) =81a(7) =168a(8) =350a(9) =729a(10) =1516a(11) =3154a(12) =6561a(13) =13647a(14) =28387a(15) =59049a(16) =122826a(17) =255490a(18) =531441a(19) =1105441a(20) =2299411a(21) =4782969a(22) =9948976a(23) =20694704a(24) =43046721a(25) =89540787a(26) =186252344a(27) =387420489a(28) =805867091a(29) =1676271101