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Search: id:A143026
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| A143026 |
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Positive integers n such that the fourth power of the number of positive divisors of n equals n. |
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+0
1
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OFFSET
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1,2
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COMMENT
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625=5^4, 6561=3^8, 4100625=(3^8)(5^4).
There are no more terms in the sequence.
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REFERENCES
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T. Andreescu, D. Andrica and Z. Feng, 104 Number Theory Problems (from the training of the USA IMO team), Birkhauser, Boston, 2007, Advanced problem # 19, pp.85,145,146.
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EXAMPLE
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625 has 5 divisors (1,5,25,125 and 625) and 5^4 = 625.
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CROSSREFS
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Sequence in context: A046755 A016816 A046756 this_sequence A064781 A055868 A106321
Adjacent sequences: A143023 A143024 A143025 this_sequence A143027 A143028 A143029
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KEYWORD
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fini,nonn,full
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AUTHOR
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Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 11 2008
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