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 A180691 #13 Oct 05 2019 04:55:23
%S A180691 1,20736,35831808,429981696,5159780352,61917364224,743008370688,
%T A180691 8916100448256,953962166440690129601298432,106993205379072,
%U A180691 11447545997288281555215581184,12,137370551967459378662586974208,144,15407021574586368,1648446623609512543951043690496
%N A180691 Smallest power of 12 that begins with n.
%t A180691 tlv=12^Range[0,40]; f[n_]:=Module[{idn=IntegerDigits[n],len}, len=Length[idn]; First[Select[tlv, Take[IntegerDigits[#],len]==idn&]]]; Table[f[i],{i,20}]//Quiet (* _Harvey P. Dale_, Feb 14 2011 *)
%Y A180691 Cf. A001021, A180689, A180692, A180693.
%K A180691 nonn,base
%O A180691 1,2
%A A180691 _Daniel Mondot_, Sep 17 2010
%E A180691 More terms from _Harvey P. Dale_, Feb 14 2011