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A374424
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a(n) is the smallest number which can be represented as the sum of 4 distinct positive n-th powers in exactly 2 ways, or -1 if no such number exists.
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11
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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(5) = 4062500 = 1^5 + 14^5 + 16^5 + 19^5 = 5^5 + 10^5 + 15^5 + 20^5.
a(6) = 160426515 = 1^6 + 3^6 + 19^6 + 22^6 = 1^6 + 10^6 + 15^6 + 23^6.
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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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EXTENSIONS
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STATUS
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approved
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