3-smooth numbers: numbers of the form 2^i*3^j with i, j >= 0.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =9a(7) =12a(8) =16a(9) =18a(10) =24a(11) =27a(12) =32a(13) =36a(14) =48a(15) =54a(16) =64a(17) =72a(18) =81a(19) =96a(20) =108a(21) =128a(22) =144a(23) =162a(24) =192a(25) =216a(26) =243a(27) =256a(28) =288a(29) =324