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 A146026 #23 May 03 2019 08:40:29 %S A146026 0,1,2,3,8281,8282,8283 %N A146026 Numbers that can be written from base 2 to base 9 using only the digits 0 to 3. %C A146026 Conjectured to be complete. %C A146026 Checked up to 2^16384 (≈ 1.2*10^4932) on Oct 31 2008. - _Daniel Mondot_, Jan 17 2016 %C A146026 Checked up to 2^65520 (≈ 3*10^19723) on Nov 13 2008. - _Daniel Mondot_, Jan 17 2016 %C A146026 It is a plausible conjecture that there are no more terms, but this has not been proved. - _N. J. A. Sloane_, Nov 17 2017 %H A146026 Stuart A. Burrell, Han Yu, <a href="https://arxiv.org/abs/1905.00832">Digit expansions of numbers in different bases</a>, arXiv:1905.00832 [math.NT], 2019. %t A146026 Select[Range[0, 10^5], Function[n, Times @@ Boole@ Map[Max@ IntegerDigits[n, #] <= 3 &, Range[2, 9]] > 0]] (* _Michael De Vlieger_, Aug 15 2016 *) %Y A146026 cf. A146025, A146027, A131646, A275600 %K A146026 nonn,base %O A146026 1,3 %A A146026 _Daniel Mondot_, Oct 27 2008