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 A031146 #26 Jun 15 2018 10:40:13
%S A031146 0,10,42,43,79,88,100,102,189,198,242,250,252,263,305,262,370,306,368,
%T A031146 383,447,464,496,672,466,557,630,629,628,654,657,746,771,798,908,913,
%U A031146 917,906,905,1012,1113,988,1020,989,1044,1114,1120,1118,1221,1218,1255
%N A031146 Exponent of the least power of 2 having exactly n zeros in its decimal representation.
%H A031146 T. D. Noe, <a href="/A031146/b031146.txt">Table of n, a(n) for n = 0..1000</a>
%e A031146 a(3) = 43 since 2^m contains 3 0's for m starting with 43 (2^43 = 8796093022208) and followed by 53, 61, 69, 70, 83, 87, 89, 90, 93, ...
%t A031146 a = {}; Do[k = 0; While[ Count[ IntegerDigits[2^k], 0] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a (* _Robert G. Wilson v_, Jun 12 2004 *)
%t A031146 nn = 100; t = Table[0, {nn}]; found = 0; k = 0; While[found < nn, k++; cnt = Count[IntegerDigits[2^k], 0]; If[cnt <= nn && t[[cnt]] == 0, t[[cnt]] = k; found++]]; t = Join[{0}, t] (* _T. D. Noe_, Mar 14 2012 *)
%o A031146 (PARI) A031146(n)=for(k=0, oo, #select(d->!d, digits(2^k))==n&&return(k)) \\ _M. F. Hasler_, Jun 15 2018
%Y A031146 Cf. A000079, A007377, A031147, A006889.
%Y A031146 Cf. A063555 (analog for 3^k), A063575 (for 4^k), A063585 (for 5^k), A063596 (for 6^k), A063606 (for 7^k), A063616 (for 8^k), A063626 (for 9^k).
%K A031146 base,nonn
%O A031146 0,2
%A A031146 _N. J. A. Sloane_
%E A031146 More terms from _Erich Friedman_
%E A031146 Definition clarified by _Joerg Arndt_, Sep 27 2016