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A273934 Amicable 5-tuples: (x1,...,x5) such that sigma(x1)=...=sigma(x5)=x1+...+x5, x1<x2<x3<x4<x5. Sequence gives x5 numbers. 7
61695597600, 72598125600, 78953074200, 96369633360, 96369633360, 103073639760, 99692021520, 100469023200, 109446377040 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The 5-tuple starting with 53542288800 was given by Donovan Johnson. The common value of sigma(x) is 294821130240.
A larger 5-tuple, (55766707476480, 56992185169920, 57515254917120, 57754372515840, 57829096765440), was found by Michel Marcus on Dec 09 2013. The common value of sigma(x) is 285857616844800.
A still larger example (227491164588441600, 228507506351308800, 229862628701798400, 230878970464665600, 243752632794316800), probably the first one to be published, had been found by Yasutoshi Kohmoto in 2008, cf. link to SeqFan post.
Other terms from John Cerkan.
There are different definitions for amicable k-tuples, cf. link to MathWorld.
LINKS
Yasutoshi Kohmoto, Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v, SeqFan list, Nov 23 2008
Yasutoshi Kohmoto, Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v, SeqFan list, Dec 09 2013
Eric W. Weisstein, Amicable Triple. From MathWorld--A Wolfram Web Resource.
CROSSREFS
Cf. A036471 - A036474 and A116148 (quadruples).
Cf. A125490 - A125492 and A137231 (triples).
Sequence in context: A196753 A258424 A015431 * A017410 A017530 A216020
KEYWORD
nonn,more
AUTHOR
John Cerkan, Jun 04 2016
STATUS
approved

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Last modified July 21 11:42 EDT 2024. Contains 374472 sequences. (Running on oeis4.)