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 A102483 #34 Feb 16 2025 08:32:55 %S A102483 0,1,2,3,4,15 %N A102483 Numbers k such that 2^k contains no zeros in base 3. %C A102483 I conjectured in 1973 that there are no further terms. This question is still open. %C A102483 A104320(a(n)) = 0. - _Reinhard Zumkeller_, Mar 01 2005 %C A102483 No other terms less than 200000. - _Robert G. Wilson v_, Dec 06 2005 %C A102483 a(7) > 10^7. - _Martin Ehrenstein_, Jul 27 2021 %C A102483 If it exists, a(7) > 10^21. - _Robert Saye_, Mar 23 2022 %H A102483 Robert I. Saye, <a href="https://arxiv.org/abs/2202.13256">On two conjectures concerning the ternary digits of powers of two</a>, J. Integer Seq. 25 (2022) Article 22.3.4. %H A102483 N. J. A. Sloane, <a href="http://neilsloane.com/doc/persistence.html">The persistence of a number</a>, J. Recreational Math., 6 (1973), 97-98. %H A102483 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Ternary.html">Ternary</a> %t A102483 Select[ Range@1000, FreeQ[ IntegerDigits[2^#, 3], 0] &] (* _Robert G. Wilson v_, Dec 06 2005 *) %o A102483 (PARI) for (n=0, 100, if (vecmin(digits(2^n, 3)), print1(n, ", "))) \\ _Michel Marcus_, Mar 25 2015 %Y A102483 Cf. A007377, A004642, A346497. %K A102483 nonn,base,hard %O A102483 1,3 %A A102483 _N. J. A. Sloane_, Feb 25 2005