Numbers of form 2^i*9^j, with i, j >= 0.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =9a(5) =16a(6) =18a(7) =32a(8) =36a(9) =64a(10) =72a(11) =81a(12) =128a(13) =144a(14) =162a(15) =256a(16) =288a(17) =324a(18) =512a(19) =576a(20) =648a(21) =729a(22) =1024a(23) =1152a(24) =1296a(25) =1458a(26) =2048a(27) =2304a(28) =2592a(29) =2916