Numbers of form 6^i*9^j, with i, j >= 0.

Terms

a(0) =1a(1) =6a(2) =9a(3) =36a(4) =54a(5) =81a(6) =216a(7) =324a(8) =486a(9) =729a(10) =1296a(11) =1944a(12) =2916a(13) =4374a(14) =6561a(15) =7776a(16) =11664a(17) =17496a(18) =26244a(19) =39366a(20) =46656a(21) =59049a(22) =69984a(23) =104976a(24) =157464a(25) =236196a(26) =279936a(27) =354294a(28) =419904a(29) =531441