Numbers whose base-7 and base-9 expansions have no digits in common.

Terms

a(0) =7a(1) =8a(2) =14a(3) =16a(4) =17a(5) =22a(6) =24a(7) =25a(8) =26a(9) =28a(10) =29a(11) =30a(12) =32a(13) =33a(14) =34a(15) =35a(16) =36a(17) =37a(18) =38a(19) =40a(20) =43a(21) =44a(22) =45a(23) =46a(24) =48a(25) =49a(26) =50a(27) =51a(28) =52a(29) =53