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A345363
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Composite numbers that are the exact average of three consecutive primes.
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0
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511, 537, 999, 1073, 1239, 1461, 1501, 1541, 1763, 1773, 1899, 1917, 2071, 2181, 2401, 2409, 2449, 3059, 3069, 3179, 3201, 3509, 3807, 4081, 4101, 4179, 4387, 4399, 4437, 4467, 4559, 4607, 4681, 4705, 4879, 5089, 5211, 5257, 5271, 5373, 5429, 5757, 5829, 6415, 6621, 6671
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OFFSET
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1,1
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LINKS
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EXAMPLE
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511 is composite and the average of the consecutive primes 503, 509 and 521. Thus, 511 is in the sequence.
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MATHEMATICA
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Select[Table[(Prime[n] + Prime[n + 1] + Prime[n + 2])/3, {n, 2000}], IntegerQ[#] && ! PrimeQ[#] &]
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CROSSREFS
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Cf. A242218 (subsequence of semiprimes).
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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