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, 92709463147897837085761925410587, 2865014852390475710679572105323242035759805416923029389510561523

Offset

0,2

Links

Table of n, a(n) for n=0..24.

Mathematica

Select[3^Range[0, 1000], !MemberQ[Differences[IntegerDigits[#]], 0]&] (* Vincenzo Librandi, Jan 22 2026 *)

Prog

(Magma) [3^n : n in [0..1000] |not exists{i : i in [1..#d-1] | d[i+1] - d[i] eq 0} where d is Intseq(3^n) ]; // Vincenzo Librandi, Jan 22 2026

Crossrefs

Cf. A043096, A050724.

Subsequence of A000244.

Sequence in context: A352779 A140429 A133494 * A238939 A351345 A351344

Adjacent sequences: A050730 A050731 A050732 * A050734 A050735 A050736

Keyword

nonn,base

Author

Patrick De Geest, Sep 15 1999

Extensions

a(23)-a(24) from Vincenzo Librandi, Jan 22 2026

Status

approved