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 A131629 #12 Jun 08 2025 03:34:40
%S A131629 0,2,3,4,6,7,8,10,11,14,19,27,28,34,40,50,55,84
%N A131629 Numbers k such that the decimal expansion of 3^k contains no 3.
%C A131629 I conjecture that 84 is the last term.
%t A131629 Join[{0}, Select[ Range@10000, FreeQ[ IntegerDigits[3^# ], 3] &]]
%o A131629 (Magma) [n: n in [0..1000] | not 3 in Intseq(3^n) ]; // _Vincenzo Librandi_, May 06 2015
%Y A131629 Cf. similar sequences listed in A131613.
%Y A131629 Cf. A007377, A136291.
%K A131629 base,fini,nonn
%O A131629 1,2
%A A131629 _Shyam Sunder Gupta_, Sep 01 2007
%E A131629 Initial 0 added and Mathematica code adapted by _Vincenzo Librandi_, May 06 2015