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 A031147 #20 Sep 10 2024 12:40:59
%S A031147 1,1024,4398046511104,8796093022208,604462909807314587353088,
%T A031147 309485009821345068724781056,1267650600228229401496703205376,
%U A031147 5070602400912917605986812821504,784637716923335095479473677900958302012794430558004314112
%N A031147 Smallest power of 2 containing exactly n zeros.
%F A031147 a(n) = 2^A031146(n). - _M. F. Hasler_, Jun 15 2018 (corrected by _Sean A. Irvine_, Apr 11 2020)
%t A031147 Table[SelectFirst[{#,DigitCount[#,10,0]}&/@(2^Range[0,2000]),#[[2]]==n&],{n,0,8}][[;;,1]] (* _Harvey P. Dale_, Sep 10 2024 *)
%o A031147 (PARI) A031147(n)=for(k=n, oo, #select(d->!d, digits(2^k))==n&&return(2^k)) \\ _M. F. Hasler_, Jun 15 2018
%Y A031147 Cf. A031146.
%K A031147 nonn,easy,base
%O A031147 0,2
%A A031147 _N. J. A. Sloane_
%E A031147 More terms from _Erich Friedman_
%E A031147 a(8) added by _M. F. Hasler_, Jun 16 2018