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A074966
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a(n) = least k such that n^n + k is prime.
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10
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1, 1, 2, 1, 12, 7, 4, 43, 10, 19, 62, 35, 16, 27, 28, 13, 74, 107, 18, 91, 32, 87, 14, 95, 96, 43, 68, 135, 120, 19, 58, 7, 58, 63, 54, 31, 42, 115, 10, 157, 110, 13, 4, 403, 122, 457, 534, 37, 18, 31, 226, 253, 20, 193, 102, 177, 392, 45, 194, 257, 102, 79, 454, 231, 306
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OFFSET
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1,3
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COMMENTS
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"Are there any n except 1, 2 and 4 that make n^n + 1 a prime? He [Sierpiński] has shown that if such a prime exists it is greater than 10^30000." - Ogilvy and Anderson
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REFERENCES
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C. Stanley Ogilvy and John T. Anderson, Excursions in Number Theory. Dover. New York: 1988. Page 82.
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LINKS
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MATHEMATICA
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Array[Block[{k = 1}, While[! PrimeQ[k + #], k++]; k] &[#^#] &, 65] (* Michael De Vlieger, Jul 06 2018 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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