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Search: id:A160804
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| A160804 |
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Consider a permutation K = (k(1),k(2),...k(A000005(n))) of the positive divisors of n. Consider the partial sums S= sum{j=1 to m} k(j), 1<=m<=A000005(n). Then, a(n) = the minimum number, for any permutation K, of partial sums S that are coprime to n. |
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2
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| 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 2, 1, 1, 0, 2, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 2, 0, 2, 0, 1
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OFFSET
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1,21
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EXAMPLE
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The divisors of 12 are 1,2,3,4,6,12. If the permutation K is, for example, (12,6,3,1,2,4), then the partial sums are: 12=12, 12+6=18, 12+6+3=21, 12+6+3+1=22, 12+6+3+1+2=24, and 12+6+3+1+2+4=28. None of these sums are coprime to 12, proving that the minimum number of partial sums coprime to 12 = a(12) = 0.
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CROSSREFS
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Cf. A151613.
Sequence in context: A070092 A123671 A090418 this_sequence A085854 A117145 A083912
Adjacent sequences: A160801 A160802 A160803 this_sequence A160805 A160806 A160807
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KEYWORD
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more,nonn
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AUTHOR
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Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), May 26 2009
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EXTENSIONS
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Extended thru a(59) by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jun 15 2009
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