Sums of 2 distinct powers of 6.

Terms

a(0) =7a(1) =37a(2) =42a(3) =217a(4) =222a(5) =252a(6) =1297a(7) =1302a(8) =1332a(9) =1512a(10) =7777a(11) =7782a(12) =7812a(13) =7992a(14) =9072a(15) =46657a(16) =46662a(17) =46692a(18) =46872a(19) =47952a(20) =54432a(21) =279937a(22) =279942a(23) =279972a(24) =280152a(25) =281232a(26) =287712a(27) =326592a(28) =1679617a(29) =1679622