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A159298
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Numbers n such that n*10^n*(10^n - 1)/9 + 1 is prime.
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0
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OFFSET
| 1,2
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COMMENTS
| There are no more terms up to n = 4000 (cf. link).
There are no more terms up to n = 14600. [From Jason Earls (zevi_35711(AT)yahoo.com), Nov 30 2009]
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REFERENCES
| J. Earls, Mathematical Bliss, Pleroma Publications, 2009, page 55. ASIN: B002ACVZ6O [From Jason Earls (zevi_35711(AT)yahoo.com), Nov 22 2009]
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LINKS
| Jason Earls, Biography: Enrico Bombieri, Fields Medal winner
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EXAMPLE
| For n = 5, n*10^n*(10^n - 1)/9 + 1 is the prime 5555500001. Hence 5 is in the sequence.
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PROG
| (MAGMA) [ x[1]: x in [ < n, Integers()!(n*10^n*(10^n - 1)/9 + 1) >: n in [1..186] ] | IsPrime(x[2]) ];
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CROSSREFS
| Cf. A002275 (repunits: (10^n - 1)/9).
Sequence in context: A080284 A193458 A071861 * A173376 A128523 A068311
Adjacent sequences: A159295 A159296 A159297 * A159299 A159300 A159301
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KEYWORD
| more,nonn
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AUTHOR
| Lekraj Beedassy (blekraj(AT)yahoo.com), Apr 09 2009
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EXTENSIONS
| Edited by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Apr 11 2009
a(8) from Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 03 2010
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