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A007666
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a(n) = smallest number k such that k^n is sum of n n-th powers, or 0 if no solution exists.
(Formerly M3753)
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4
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OFFSET
| 1,2
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COMMENTS
| a(7) = 568 and a(8) = 1409. - J. Lowell, jhbubby(AT)mindspring.com, Jul 25 2007
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REFERENCES
| N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, 164.
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LINKS
| Author?, FAQ File
Author?, Title
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EXAMPLE
| 5^2 = 3^2+4^2; 6^3 = 3^3+4^3+5^3; 353^4 = 30^4+120^4+272^4+315^4; 72^5 = 19^5+43^5+46^5+47^5+67^5
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CROSSREFS
| k^n = T(n, 1)^n + .. + T(n, n)^n, where T() is given in A061988.
Sequence in context: A042089 A156191 A042387 * A064177 A042721 A048658
Adjacent sequences: A007663 A007664 A007665 * A007667 A007668 A007669
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KEYWORD
| nonn,hard,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com)
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EXTENSIONS
| The next term has been claimed to be 1141, but this is incorrect. In fact 1141 is the sum of seven 6th powers. - Jud McCranie (JudMcCranie(AT)ugaalum.uga.edu), Jun 10 2007
a(6) is either 0 (no solution) or greater than 272580 (see above link to resta.htm page). - Jon Schoenfield, Jun 10 2007
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