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 A046297 #17 Oct 14 2019 03:45:54 %S A046297 103,267,279,287,404,503,511,515,657,685,745,763,883,890,922,946,973, %T A046297 991,1011,1087,1114,1121,1164,1197,1209,1272,1274,1283,1302,1316,1328, %U A046297 1360,1378,1432,1445,1478,1509,1511,1542,1565,1571,1584,1627,1672,1678 %N A046297 Numbers k such that 2^k contains 2^11=2048 as its largest proper substring of the form 2^m. %e A046297 2^103 = 10141{2048}01825835211973625643008. %t A046297 sub2[n_] := Block[{s = ToString[2^n], k = n-1}, While[k >= 0 && ! StringContainsQ[ s, ToString[2^k]], k--]; k]; Select[Range[1000], sub2[#] == 11 &] (* _Giovanni Resta_, Oct 14 2019 *) %Y A046297 Cf. A033921. %K A046297 nonn,base %O A046297 1,1 %A A046297 _Patrick De Geest_, Jun 15 1998