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A259305
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Numbers n such that there exists an x!=n that makes {x,x,x,n} an amicable multiset.
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9
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756000, 1220940, 1437480, 1973160, 5019840, 9058140, 9703260, 11058480, 11641680, 13085280, 17089920, 18117000, 19370880, 21282912, 21628080, 25295760, 25585560, 26936640, 27763560, 28191240, 29104200, 29203020, 30450420, 32839560, 33279120, 33398820
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OFFSET
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1,1
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COMMENTS
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We call the multiset {x,x,x,n} amicable iff sigma(x)=sigma(n)=x+x+x+n.
For the x values, see A259304.
If the condition x!=n were dropped, the terms from A027687 would also belong here.
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LINKS
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John Cerkan, Table of n, a(n) for n = 1..1000
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PROG
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(PARI) isOK(n) = x=(sigma(n)-n)/3; x>0&x!=n&denominator(x)==1&sigma(x)==3*x+n
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CROSSREFS
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Cf. A027687, A259307, A259304, A259302, A259303, A259306, A036471.
Sequence in context: A290161 A244308 A273971 * A172586 A172571 A172670
Adjacent sequences: A259302 A259303 A259304 * A259306 A259307 A259308
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KEYWORD
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nonn
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AUTHOR
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Jeppe Stig Nielsen, Jun 23 2015
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STATUS
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approved
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