Reverse and add (in base 3).

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =32a(6) =96a(7) =160a(8) =320a(9) =960a(10) =1600a(11) =2880a(12) =3520a(13) =6080a(14) =11200a(15) =21440a(16) =62400a(17) =86080a(18) =169280a(19) =338560a(20) =648248a(21) =1902840a(22) =3281200a(23) =6404832a(24) =6510784a(25) =12950936a(26) =25744192a(27) =51882584a(28) =156278688a(29) =261609208