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A109387
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Numbers n such that 3^n - n^3 is prime.
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9
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1, 4, 10, 52, 112, 212, 346, 406, 512, 13904, 76610, 89746
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Terms <= 512 correspond to certified primes. Next term after 13904 is greater than 20000.
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EXAMPLE
| a(2)=4 because 3^4 -4^3 = 17 is prime
3^10 - 10^3 = 58049 is prime, hence 10 is a term.
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MATHEMATICA
| Do[If[PrimeQ[3^n - n^3], Print[n]], {n, 1, 20000}]
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CROSSREFS
| Sequence in context: A081565 A151611 A032495 * A018844 A007027 A192444
Adjacent sequences: A109384 A109385 A109386 * A109388 A109389 A109390
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KEYWORD
| hard,more,nonn
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AUTHOR
| Ryan Propper (rpropper(AT)stanford.edu), Jun 26 2005
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EXTENSIONS
| Two more terms from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 26 2008
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