A050733 Numbers of form 3^k (values of k see A050724) containing no pair of consecutive equal digits (probably finite).

1, 3, 9, 27, 81, 243, 729, 2187, 6561, 19683, 59049, 1594323, 4782969, 14348907, 43046721, 129140163, 387420489, 10460353203, 31381059609, 282429536481, 2541865828329, 109418989131512359209, 30903154382632612361920641803529