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%I #10 Apr 12 2024 09:51:27
%S 0,7,70,88,97,700,707,878,880,948,970,997,7000,7007,7070,8780,8798,
%T 8800,8947,9480,9700,9898,9970,9997,70000,70007,70070,70700,70707,
%U 87798,87800,87980,88000,89448,89470,94800,97000,98980,99448,99700,99970,99997,700000,700007,700070,700700,707000,707070,877898,877980,877998,878000,879800
%N Numbers k such that k and k^2 use only the digits 0, 4, 7, 8 and 9.
%C Generated with DrScheme.
%H Jonathan Wellons, <a href="/A136959/b136959.txt">Table of n, a(n) for n = 1..1058</a>
%H J. Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]
%e 8989409879898^2 = 80809489988807774784490404.
%t With[{c={0,4,7,8,9}},Select[FromDigits/@Tuples[c,6],SubsetQ[ c, IntegerDigits[ #^2]]&]] (* _Harvey P. Dale_, Jun 02 2019 *)
%K base,nonn
%O 1,2
%A Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
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