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Search: id:A163418
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| A163418 |
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Primes of the form ((p-1)/2)^2+((p+1)/2), where p is prime. |
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+0
13
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| 3, 7, 13, 31, 43, 73, 211, 241, 421, 463, 1123, 1723, 2551, 2971, 4831, 5701, 6163, 8011, 8191, 9901, 11131, 12433, 14281, 17293, 19183, 20023, 23563, 24181, 28393, 30103, 31153, 35911, 37831, 43891, 46441, 53593, 60271, 77563, 83233, 86143
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Subsequence of A002383.
((3-1)/2)^2+((3+1)/2)=1+2=3, ((5-1)/2)^2+((5+1)/2)=4+3=7, ((7-1)/2)^2+((7+1)/2)=9+4=13,..
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MATHEMATICA
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f[n_]:=((p-1)/2)^2+((p+1)/2); lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], AppendTo[lst, f[p]]], {n, 6!}]; lst
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CROSSREFS
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Cf. A162652
Sequence in context: A162869 A079018 A002383 this_sequence A161218 A068679 A006978
Adjacent sequences: A163415 A163416 A163417 this_sequence A163419 A163420 A163421
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KEYWORD
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nonn,easy
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AUTHOR
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Vladimir Orlovsky (4vladimir(AT)gmail.com), Jul 27 2009
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EXTENSIONS
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Comment by Charles R Greathouse IV Aug 11 2009
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