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A224321
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Primes without "7" as a digit that remain prime when any single digit is replaced with "7".
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2
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2, 3, 5, 11, 13, 19, 31, 41, 43, 61, 109, 139, 251, 643, 4933, 9433, 36493, 191416111, 1304119699
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OFFSET
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1,1
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COMMENTS
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No more terms < 10^13.
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LINKS
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MATHEMATICA
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lst = {}; n = 7; Do[If[PrimeQ[p], i = IntegerDigits[p]; If[FreeQ[i, n], t = 0; s = IntegerLength[p]; Do[If[PrimeQ@FromDigits@Insert[Drop[i, {d}], n, d], t++, Break[]], {d, s}]; If[t == s, AppendTo[lst, p]]]], {p, 36493}]; lst
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CROSSREFS
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KEYWORD
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base,more,nonn
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AUTHOR
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STATUS
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approved
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