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 A119866 #7 Aug 12 2025 03:19:23 %S A119866 10541,33334,47141,57735,66667,105409,105410,105411,105412,105413, %T A119866 149071,149072,149073,182574,182575,182576,210818,210819,235702, %U A119866 235703,258198,258199,278886,278887,298141,298142,316227,333332,333333,333334 %N A119866 Numbers whose square starts with 5 identical digits. %e A119866 10541^2=111112681, 33334^2=1111155556. %t A119866 Select[ Range[ 100, 500000 ], Length[ Union[ Take[ IntegerDigits[ #^2 ], 5 ] ] ] == 1 & ] (* _Jonathan Vos Post_, Aug 29 2007 *) %Y A119866 Cf. A119511, A131573, A132391, A133183. %K A119866 nonn,base %O A119866 1,1 %A A119866 _Zak Seidov_, Aug 04 2006