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A058911
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Numbers k such that k^k + k + 1 is prime.
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3
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OFFSET
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1,3
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COMMENTS
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LINKS
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EXAMPLE
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a(2) = 2 because 2^2 + 2 + 1 = 7.
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MATHEMATICA
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Do[ If[ PrimeQ[ n^n + n + 1], Print[n]], {n, 1, 700} ]
Join[{0}, Select[Range[470], PrimeQ[#^#+#+1]&]] (* Harvey P. Dale, Dec 11 2022 *)
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PROG
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(PARI) f2(n, k) = for(x=1, n, y=x^x+x+k; if(ispseudoprime(y), print1(x", "))) \\ Cino Hilliard, Jan 07 2005
(PFGW) ABC2 $a^$a + $a + 1
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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STATUS
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approved
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