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A077782
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Numbers k such that (10^k - 1) - 5*10^floor(m/2) is a palindromic wing prime (a.k.a. near-repdigit palindromic prime).
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2
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OFFSET
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1,1
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COMMENTS
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Prime versus probable prime status and proofs are given in the author's table.
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REFERENCES
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C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.
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LINKS
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FORMULA
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EXAMPLE
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29 is a term because (10^29 - 1) - 5*10^14 = 99999999999999499999999999999.
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MATHEMATICA
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Do[ If[ PrimeQ[10^n - 5*10^Floor[n/2] - 1], Print[n]], {n, 3, 50900, 2}] (* Robert G. Wilson v, Dec 16 2005 *)
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CROSSREFS
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KEYWORD
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more,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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