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A091414
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a(n) = the least number k such that k can be represented as the sum of n positive nth-powers in at least 2 ways.
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0
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50, 251, 259, 4097, 570947, 73310705, 647282661, 79327628290, 1077347903894, 1761813250036143, 2343908545594901
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,1
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COMMENTS
| a(11) = 2^11 + 2^11 + 2^11 + 2^11 + 8^11 + 10^11 + 10^11 + 15^11 + 22^11 + 22^11 + 22^11 = 3^11 + 5^11 + 5^11 + 5^11 + 6^11 + 9^11 + 11^11 + 12^11 + 17^11 + 20^11 + 24^11. a(12) = 2^12 + 2^12 + 2^12 + 2^12 + 2^12 + 2^12 + 2^12 + 9^12 + 9^12 + 9^12 + 15^12 + 19^12 = 3^12 + 5^12 + 5^12 + 10^12 + 10^12 + 10^12 + 10^12 + 12^12 + 12^12 + 17^12 + 17^12 + 18^12. a(13) > 876*10^15. a(14) > 799*10^15. a(15) > 115*10^16. [From Donovan Johnson (donovan.johnson(AT)yahoo.com), Sep 14 2008]
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EXAMPLE
| a(3) = 251 because 251 = 1^3 + 5^3 + 5^3 = 2^3 + 3^3 + 6^3 and it is the smallest number that can be represented two ways as the sum of three third powers.
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CROSSREFS
| Sequence in context: A186843 A197971 A091883 * A186123 A205355 A172519
Adjacent sequences: A091411 A091412 A091413 * A091415 A091416 A091417
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KEYWORD
| more,nonn
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AUTHOR
| Gabriel Cunningham (gcasey(AT)mit.edu), Mar 02 2004
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EXTENSIONS
| More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Mar 09 2006
a(11)-a(12) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Sep 14 2008
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