Palindromic numbers in bases 3 and 7 written in base 10.

Terms

a(0) =0a(1) =1a(2) =2a(3) =4a(4) =8a(5) =16a(6) =40a(7) =100a(8) =121a(9) =142a(10) =164a(11) =242a(12) =328a(13) =400a(14) =1312a(15) =8200a(16) =9103a(17) =14762a(18) =54008a(19) =76024a(20) =108016a(21) =112048a(22) =233920a(23) =532900a(24) =639721a(25) =741586a(26) =2585488a(27) =3316520a(28) =11502842a(29) =24919360