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%I #18 May 10 2024 08:51:10
%S 1,2,5,11,12,15,21,112,211,145415,11145511
%N Numbers k such that k and k^2 use only the digits 1, 2, 4 and 5.
%C Generated with DrScheme.
%C No additional terms < 10^39. - _Michael S. Branicky_, Jul 05 2021
%H Jonathan Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]
%e 145415^2 = 21145522225.
%t With[{c={1,2,4,5}},Select[Flatten[Table[FromDigits/@Tuples[c,n],{n,10}]],SubsetQ[c,IntegerDigits[#^2]]&]] (* _Harvey P. Dale_, Sep 15 2019 *)
%K base,nonn,more
%O 1,2
%A Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008