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 A069028 #4 Aug 05 2015 11:50:47
%S A069028 1,3,9,729,19683,4782969,94143178827,847288609443,7625597484987,
%T A069028 16677181699666569,328256967394537077627,26588814358957503287787,
%U A069028 717897987691852588770249,381520424476945831628649898809
%N A069028 Powers of 3 with strictly increasing sum of digits.
%H A069028 Charles R Greathouse IV, <a href="/A069028/b069028.txt">Table of n, a(n) for n = 1..167</a>
%o A069028 (PARI) print1(r=t=1); for(n=1,99, s=sumdigits(t*=3); if(s>r,r=s; print1(", "t))) \\ _Charles R Greathouse IV_, Aug 05 2015
%Y A069028 Cf. A069027.
%K A069028 nonn,base
%O A069028 1,2
%A A069028 _Amarnath Murthy_, Apr 02 2002
%E A069028 More terms from Larry Reeves (larryr(AT)acm.org), Jun 26 2002
%E A069028 a(11)-a(14) from _Charles R Greathouse IV_, Aug 05 2015