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A136861
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Numbers k such that k and k^2 use only the digits 0, 1, 4, 6 and 8.
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1
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0, 1, 4, 8, 10, 40, 41, 80, 100, 104, 108, 400, 401, 408, 410, 641, 800, 801, 804, 1000, 1004, 1008, 1040, 1080, 4000, 4001, 4008, 4010, 4080, 4100, 6410, 6441, 8000, 8001, 8004, 8010, 8040, 10000, 10004, 10008, 10040, 10080, 10400, 10401, 10800, 10801, 40000, 40001, 40008, 40010, 40080, 40100, 40604, 40800, 41000, 64100, 64410, 66441, 80000, 80001
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OFFSET
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1,3
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COMMENTS
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Generated with DrScheme.
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LINKS
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EXAMPLE
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68418648641^2 = 4681111481860611146881.
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MATHEMATICA
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id2Q[n_]:=Module[{idn2=IntegerDigits[n^2], digs={0, 1, 4, 6, 8}}, And@@Table[ MemberQ[digs, idn2[[i]]], {i, Length[idn2]}]]; Select[Union[Flatten[ Table[FromDigits/@Tuples[{0, 1, 4, 6, 8}, n], {n, 5}]]], id2Q] (* Harvey P. Dale, Aug 19 2012 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
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STATUS
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approved
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