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Search: id:A051856
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| A051856 |
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Numbers n such that (n!)^2+n!+1 is prime. |
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5
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OFFSET
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1,3
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REFERENCES
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H. Dubner, Factorial and primorial primes, J. Rec. Math., 19(No. 3, 1987)
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LINKS
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C. K. Caldwell, The Prime Pages
C. Nash, Prime Form
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EXAMPLE
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6 is in the sequence because (6!)^2+6!+1=519121 is prime.
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MATHEMATICA
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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
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Cf. A002981, A002982, A046029, A046029.
Sequence in context: A065199 A033179 A067244 this_sequence A084811 A135236 A029962
Adjacent sequences: A051853 A051854 A051855 this_sequence A051857 A051858 A051859
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KEYWORD
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nonn
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AUTHOR
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Andrew Walker (ajw01(AT)uow.edu.au), Dec 13 1999
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EXTENSIONS
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Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 08 2008
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