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 A131627 #10 Sep 08 2022 08:45:31 %S A131627 1,2,3,5,6,10,14,18,25,27,29,33,37,43 %N A131627 Numbers k such that the decimal expansion of 3^k contains no 1. %C A131627 I conjecture that 43 is the last term. %t A131627 Select[ Range@10000, FreeQ[ IntegerDigits[3^# ], 1] &] %o A131627 (Magma) [n: n in [0..1000] | not 1 in Intseq(3^n) ]; // _Vincenzo Librandi_, May 06 2015 %Y A131627 Cf. similar sequences listed in A131613. %Y A131627 Cf. A007377. %K A131627 base,fini,nonn %O A131627 1,2 %A A131627 _Shyam Sunder Gupta_, Sep 01 2007