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Search: id:A137446
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| A137446 |
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Positive numbers n such that n^2 +- (n-1) are primes. |
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+0
1
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| 2, 3, 4, 6, 9, 13, 15, 16, 21, 28, 39, 55, 60
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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2^2 +- 1 -> (3,4) Primes,
3^2 +- 2 -> (7,11) Primes,
13^2 +- 12 -> (157,181) Prime,...
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MATHEMATICA
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Select[Range[500], PrimeQ[ #^2-(#-1)]&&PrimeQ[ #^2+(#-1)]&]
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CROSSREFS
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Sequence in context: A057285 A057287 A056751 this_sequence A097557 A123648 A129632
Adjacent sequences: A137443 A137444 A137445 this_sequence A137447 A137448 A137449
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KEYWORD
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nonn
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AUTHOR
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Vladimir Orlovsky (4vladimir(AT)gmail.com), Apr 21 2008
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