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A155508
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Lesser of emirps (pairs) with digits 1 and 9 only.
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3
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199, 91199, 111119, 111919, 119191, 991999, 1191119, 1191191, 1191991, 11111911, 11191991, 11919991, 19111991, 91111199, 111111199, 111199199, 191111119, 199991999, 919919999, 1111111999, 1191111991, 1199111191, 1911199999
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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Flatten[Table[Select[Subsets[Select[FromDigits/@Tuples[{1, 9}, n], PrimeQ], {2}], AllTrue[#, PrimeQ]&&#[[1]]==IntegerReverse[#[[2]]]&][[All, 1]], {n, 3, 10}]/.{}->Nothing] (* Harvey P. Dale, Aug 21 2020 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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