This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A238939 #20 Oct 07 2023 21:38:16 %S A238939 1,3,9,27,81,243,729,2187,6561,19683,177147,531441,1594323,4782969, %T A238939 1162261467,94143178827,282429536481,2541865828329,7625597484987, %U A238939 22876792454961,617673396283947,16677181699666569,278128389443693511257285776231761 %N A238939 Powers of 3 without the digit '0' in their decimal expansion. %C A238939 Conjectured to be finite and complete. See the OEIS wiki page for further information, references and links. %H A238939 M. F. Hasler, <a href="https://oeis.org/wiki/Zeroless_powers">Zeroless powers</a>, OEIS wiki, Mar 07 2014. %F A238939 a(n) = 3^A030700(n). %t A238939 Select[3^Range[0,100],DigitCount[#,10,0]==0&] (* _Paolo Xausa_, Oct 07 2023 *) %o A238939 (PARI) for(n=0,99,vecmin(digits(3^n))&& print1(3^n",")) %Y A238939 For the zeroless numbers (powers x^n), see A238938, A238939, A238940, A195948, A238936, A195908, A195946, A195945, A195942, A195943, A103662. %Y A238939 For the corresponding exponents, see A007377, A008839, A030700, A030701, A008839, A030702, A030703, A030704, A030705, A030706, A195944. %Y A238939 For other related sequences, see A052382, A027870, A102483, A103663. %K A238939 nonn,base %O A238939 1,2 %A A238939 _M. F. Hasler_, Mar 07 2014 %E A238939 Keyword:fini removed by _Jianing Song_, Jan 28 2023 as finiteness is only conjectured.