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Search: id:A088498
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| A088498 |
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Numbers n such that n^2 + n - 1 and n^2 + n + 1 are twin primes and (n + 1)*(n + 1) + n + 1 - 1 and (n + 1)*(n + 1) + n + 1 + 1 are also twin primes. |
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+0
1
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| 2, 5, 20, 455, 1364, 2204, 2450, 2729, 8540, 18485, 32198, 32318, 32780, 45863, 61214, 72554, 72560, 82145, 83258, 86603, 91370, 95198, 125333, 149330, 176888, 182909, 185534, 210845, 225665, 226253, 288419, 343160, 350090, 403940, 411500
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OFFSET
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1,1
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EXAMPLE
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20*20+20-1 =419, 419 421 twin primes and 21*21+21-1 =461, 461 463 twin primes.
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MATHEMATICA
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Select[ Range[510397], PrimeQ[ #^2 + # - 1] && PrimeQ[ #^2 + # + 1] && PrimeQ[ #^2 + 3# + 1] && PrimeQ[ #^2 + 3# + 3] & ]
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CROSSREFS
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Sequence in context: A158872 A006893 A003163 this_sequence A039777 A000941 A000131
Adjacent sequences: A088495 A088496 A088497 this_sequence A088499 A088500 A088501
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KEYWORD
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base,nonn
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AUTHOR
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Pierre CAMI (colettecami(AT)aol.com), Nov 11 2003
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EXTENSIONS
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Corrected and extended by Ray Chandler (rayjchandler(AT)sbcglobal.net) and Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 12 2003
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