Sums of two powers of 3.

Terms

a(0) =2a(1) =4a(2) =6a(3) =10a(4) =12a(5) =18a(6) =28a(7) =30a(8) =36a(9) =54a(10) =82a(11) =84a(12) =90a(13) =108a(14) =162a(15) =244a(16) =246a(17) =252a(18) =270a(19) =324a(20) =486a(21) =730a(22) =732a(23) =738a(24) =756a(25) =810a(26) =972a(27) =1458a(28) =2188a(29) =2190