Numbers of the form 3^j + 9^k, for j and k >= 0.

Terms

a(0) =2a(1) =4a(2) =10a(3) =12a(4) =18a(5) =28a(6) =36a(7) =82a(8) =84a(9) =90a(10) =108a(11) =162a(12) =244a(13) =252a(14) =324a(15) =730a(16) =732a(17) =738a(18) =756a(19) =810a(20) =972a(21) =1458a(22) =2188a(23) =2196a(24) =2268a(25) =2916a(26) =6562a(27) =6564a(28) =6570a(29) =6588