Sums of 2 distinct powers of 7.

Terms

a(0) =8a(1) =50a(2) =56a(3) =344a(4) =350a(5) =392a(6) =2402a(7) =2408a(8) =2450a(9) =2744a(10) =16808a(11) =16814a(12) =16856a(13) =17150a(14) =19208a(15) =117650a(16) =117656a(17) =117698a(18) =117992a(19) =120050a(20) =134456a(21) =823544a(22) =823550a(23) =823592a(24) =823886a(25) =825944a(26) =840350a(27) =941192a(28) =5764802a(29) =5764808