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A289259
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Numbers k such that k^2 divides 2^k + 3^k.
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1
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OFFSET
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1,2
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COMMENTS
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If k is in the sequence and p is a prime factor, coprime to k, of 2^k + 3^k, then k*p is in the sequence.
55 = 5 * 11
1971145 = 5 * 11 * 35839
3061355 = 5 * 11 * 55661
109715901845 = 5 * 11 * 35839 * 55661
340799222665 = 5 * 11 * 55661 * 111323
See Known Terms link for additional terms.
For k in the sequence, A220235(k) = 0.
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LINKS
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EXAMPLE
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2^5 + 3^5 = 275 is divisible by 5^2, so 5 is in the sequence.
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MAPLE
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select(t -> 2&^t + 3&^t mod t^2 = 0, [$1..10^6]);
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PROG
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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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a(6)-a(7) confirmed as next terms by Ray Chandler, Jul 02 2017
Known terms updated and moved to a-file by Ray Chandler, Jul 03 2017
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STATUS
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approved
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