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A067267
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Numbers n such that n, 10*n+1, 10*n+3, 10*n+7 and 10*n+9 are all primes.
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8
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19, 6949, 10111, 15727, 20149, 24799, 26041, 26881, 29587, 29947, 40213, 41203, 44257, 46747, 47701, 49057, 50023, 51061, 55921, 66109, 66643, 73939, 76819, 79579, 95947, 106501, 110083, 111781, 112213, 114679
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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a(1)=19 because 191, 193, 197 and 199 are all prime.
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MAPLE
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select(t -> andmap(isprime, [t, 10*t+1, 10*t+3, 10*t+7, 10*t+9]), [seq(i, i=1..2*10^5, 6)]); # Robert Israel, Jan 22 2018
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MATHEMATICA
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okQ[n_]:=Module[{n10=10n}, And@@PrimeQ[{n10+1, n10+3, n10+7, n10+9}]]
Select[Prime[Range[11000]], AllTrue[10#+{1, 3, 7, 9}, PrimeQ]&] (* Harvey P. Dale, Feb 23 2022 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Sudipta Das (juitech(AT)vsnl.net), Feb 21 2002
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STATUS
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approved
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