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 A067481 #13 Sep 08 2022 08:45:05
%S A067481 3,387420489,3486784401,31381059609,36472996377170786403,
%T A067481 328256967394537077627,381520424476945831628649898809,
%U A067481 3433683820292512484657849089281,30903154382632612361920641803529,3990838394187339929534246675572349035227,35917545547686059365808220080151141317043
%N A067481 Powers of 3 with initial digit 3.
%H A067481 Alois P. Heinz, <a href="/A067481/b067481.txt">Table of n, a(n) for n = 1..261</a>
%t A067481 Select[3^Range[70], First[IntegerDigits[#]]==3 &] (* _Vincenzo Librandi_, Oct 22 2018 *)
%o A067481 (Magma) [3^n: n in [1..100] | Intseq(3^n)[#Intseq(3^n)] eq 3]; // _Vincenzo Librandi_, Oct 22 2018
%o A067481 (PARI) lista(nn) = {for (n=0, nn, if (digits(x=3^n)[1] == 3, print1(x, ", ")););} \\ _Michel Marcus_, Oct 22 2018
%Y A067481 Cf. A000244, A067483.
%Y A067481 Cf. A054565.
%K A067481 base,easy,nonn
%O A067481 1,1
%A A067481 _Amarnath Murthy_, Feb 09 2002