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A306475
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Smallest nonprime number <= 10^n (n>=1) with maximum distance from a prime.
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0
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9, 93, 897, 9569, 31433, 492170, 4652430, 47326803, 436273150, 4302407536, 42652618575, 738832928197, 7177162612050, 90874329411895, 218209405436996, 1693182318746937, 80873624627235459, 804212830686678390
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OFFSET
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1,1
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COMMENTS
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Each number is a mean of two consecutive primes.
Since, except 2, primes are odd numbers, this mean is an integer.
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LINKS
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EXAMPLE
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For n=1: first prime numbers are 2, 3, 5, 7 and 11. Maximum difference between two consecutive primes is 4 between 7 and 11 thus a(1)=9.
For n=4: maximum difference between two primes less than 10^4 is 36, which occurs once: between 9551 and 9587. a(4)=(9551 + 9587)/2 = 9569.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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