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A183184
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Numbers n such that 10^(2n+1)-8*10^n-1 is prime.
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4
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OFFSET
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1,2
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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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Table of n, a(n) for n=1..10.
Patrick De Geest, World!Of Numbers, Palindromic Wing Primes (PWP's)
Makoto Kamada, Prime numbers of the form 99...99199...99
Index entries for primes involving repunits.
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FORMULA
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a(n) = (A077776(n)-1)/2.
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MATHEMATICA
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Do[If[PrimeQ[10^(2n + 1) - 8*10^n - 1], Print[n]], {n, 3000}]
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PROG
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(PARI) is(n)=ispseudoprime(10^(2*n+1)-8*10^n-1) \\ _Charles R Greathouse IV_, Jun 13 2017
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CROSSREFS
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Cf. A004023, A077775-A077798, A107123-A107127, A107648, A107649, A115073, A183174-A183187.
Sequence in context: A147259 A328740 A183315 * A115785 A218926 A360798
Adjacent sequences: A183181 A183182 A183183 * A183185 A183186 A183187
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KEYWORD
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nonn,base
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AUTHOR
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_Ray Chandler_, Dec 28 2010
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EXTENSIONS
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Added one more term from PWP table, by _Patrick De Geest_, Nov 05 2014
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STATUS
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approved
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