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 A136822 #7 Apr 12 2024 09:51:26 %S A136822 0,1,5,10,11,15,50,100,101,105,110,150,500,501,505,1000,1001,1005, %T A136822 1010,1011,1050,1100,1101,1105,1500,5000,5001,5005,5010,5011,5015, %U A136822 5050,10000,10001,10005,10010,10011,10050,10100,10105,10110,10500,11000,11001,11005,11010,11050,11205,15000,15005,50000,50001,50005,50010,50011,50015,50050,50100 %N A136822 Numbers k such that k and k^2 use only the digits 0, 1, 2 and 5. %C A136822 Generated with DrScheme %H A136822 Jonathan Wellons, <a href="/A136822/b136822.txt">Table of n, a(n) for n = 1..1165</a> %H A136822 J. Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived] %e A136822 5010102005^2 = 25101122100505020025. %K A136822 base,nonn %O A136822 1,3 %A A136822 Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008