A032831 n-th number whose set of base 7 digits is {3,4}.

3, 4, 24, 25, 31, 32, 171, 172, 178, 179, 220, 221, 227, 228, 1200, 1201, 1207, 1208, 1249, 1250, 1256, 1257, 1543, 1544, 1550, 1551, 1592, 1593, 1599, 1600, 8403, 8404, 8410, 8411, 8452, 8453, 8459, 8460, 8746, 8747, 8753