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A085304
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Least number of 4th powers required to represent n!.
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0
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1, 1, 2, 6, 9, 10, 15, 15, 9, 10, 15, 6, 12, 12
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listen;
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internal format)
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OFFSET
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0,3
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LINKS
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FORMULA
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"Shortest" solutions to n!=Sum[x(j)^4], j=1, .., m[n] with minimal value of m[n]: a(n)=Min{m[n]}. Per analogiam A084355.
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EXAMPLE
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n=6: 6!=720=625+81+14,length-of-solution=16>=a(6)
but 6!=720=2.256+13.16 seems shortest solution a(6)=15
n=7: 7!=5040=3.1296+4.256+8.16 so a(7)<=15 (uncertain);
n=8: a(8)<=9 because 8!=4.10000+1.256+4.16.
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CROSSREFS
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KEYWORD
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more,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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