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A152102
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Numbers of the form (2^p - 1)(2^q + 1) where p and q are twin primes.
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0
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231, 3999, 16771071, 68719083519, 1152921502996234239, 19342813113827469725532159, 1329227995784915871174424803370074111, 22300745198530623141528634722924057038159871
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Idea resulted from seqfan posts by Artur Jasinski (grafix(AT)csl.pl).
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MATHEMATICA
| a[n_] := If[PrimeQ[(2*n - 1)] && PrimeQ[(2*n + 1)], (2^(2*n - 1) - 1)*(2^(2*n + 1) + 1), {}]; Flatten[Table[a[n], {n, 1, 100}]]
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PROG
| (PARI) forprime(p=2, 1e3, if(isprime(q=p+2), print1((2^p-1)*(2^q+1)", "))) \\ Charles R Greathouse IV, Nov 07 2011
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CROSSREFS
| Sequence in context: A183672 A183664 A029569 * A183663 A201957 A152500
Adjacent sequences: A152099 A152100 A152101 * A152103 A152104 A152105
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KEYWORD
| nonn,easy
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AUTHOR
| Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Nov 24 2008
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