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Search: id:A162455
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| A162455 |
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Primes of the form (n!)^2 + (n!) + 1 |
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+0
1
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OFFSET
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1,1
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COMMENT
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a(6) is associated with 76!=A000142(76)=A051856(7)! and has 223 decimal digits. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Emeric Deutsch (deutsch(AT)duke.poly.edu) and Harvey P. Dale (hpd1(AT)nyu.edu), Jul 14 2009]
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FORMULA
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a(n) = A002061(A000142(A051856(n+1))+1). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 14 2009]
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MAPLE
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a := proc (n) if isprime(factorial(n)^2+factorial(n)+1) = true then factorial(n)^2+factorial(n)+1 else end if end proc: seq(a(n), n = 1 .. 76); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Jul 21 2009]
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MATHEMATICA
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Select[Table[n!^2+n!+1, {n, 150}], PrimeQ] [From Harvey P. Dale (hpd1(AT)nyu.edu), Jul 23 2009]
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CROSSREFS
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Sequence in context: A074268 A019026 A096843 this_sequence A143684 A156893 A050639
Adjacent sequences: A162452 A162453 A162454 this_sequence A162456 A162457 A162458
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KEYWORD
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easy,more,nonn
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AUTHOR
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Daniel Tisdale (daniel6874(AT)gmail.com), Jul 03 2009
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