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A082718
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Plateau and depression primes of the form 2*(10^a(n)-1)/9+7*(10^[ a(n)-1 ]+1) or (83*10^[ a(n)-1 ]+61)/9.
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2
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OFFSET
| 0,1
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COMMENTS
| Prime versus probable prime status and proofs are given in the author's table.
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REFERENCES
| C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.
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LINKS
| P. De Geest, PDP Reference Table - 929
Makoto Kamada, Factorizations of 922...229.
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FORMULA
| a(n) = A056265(n+1) + 2.
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EXAMPLE
| a(n)=13 -> 2*(10^13-1)/9+7*(10^12+1) = 9222222222229.
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CROSSREFS
| Cf. A068651, A082697-A082720.
Sequence in context: A137474 A071087 A038691 * A154821 A084741 A135623
Adjacent sequences: A082715 A082716 A082717 * A082719 A082720 A082721
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KEYWORD
| nonn,base,more
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AUTHOR
| Patrick De Geest (pdg(AT)worldofnumbers.com), Apr 13 2003.
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EXTENSIONS
| 37785 from Patrick De Geest (pdg(AT)worldofnumbers.com), Jun 26 2005
Edited by Ray Chandler (rayjchandler(AT)sbcglobal.net), Oct 20 2010
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