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A134621
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Numbers such that the arithmetic mean of the 4th power of their prime factors (taken with multiplicity) is a prime.
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15
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15, 28, 39, 48, 51, 65, 68, 76, 77, 85, 87, 93, 111, 119, 133, 141, 143, 148, 155, 161, 175, 187, 189, 209, 212, 215, 221, 225, 235, 244, 275, 287, 295, 301, 315, 316, 320, 323, 329, 355, 393, 403, 404, 411, 428, 437, 447, 451, 455, 481, 505, 508, 515, 517
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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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a(3)=39, since 39=3*13 and (3^4+13^4)/2=14321 which is prime.
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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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