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A051856
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Numbers n such that (n!)^2+n!+1 is prime.
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4
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OFFSET
| 1,3
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REFERENCES
| H. Dubner, Factorial and primorial primes, J. Rec. Math., 19 (No. 3) (1987)
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LINKS
| C. K. Caldwell, The Prime Pages
C. Nash, Prime Form [?Broken link]
M. Oakes, Re: Gaussian primorial and factorial primes, Primeforum, Dec 21 2010
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EXAMPLE
| 6 is in the sequence because (6!)^2+6!+1=519121 is prime.
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MATHEMATICA
| Do[If[PrimeQ[n!^2+n!+1], Print[n]], {n, 600}] - Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Jul 12 2003
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CROSSREFS
| Cf. A002981, A002982, A046029, A046029.
Sequence in context: A033179 A067244 A084811 * A135236 A029962 A021903
Adjacent sequences: A051853 A051854 A051855 * A051857 A051858 A051859
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KEYWORD
| nonn
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AUTHOR
| Andrew Walker (ajw01(AT)uow.edu.au), Dec 13 1999
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EXTENSIONS
| Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 08 2008
a(8)-a(10) from Serge Batalov (batalovs(AT)yahoo.com), Nov 24 2011
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