

A273930


Amicable 5tuples: (x1,...,x5) such that sigma(x1)=...=sigma(x5)=x1+...+x5, x1<x2<x3<x4<x5. Sequence gives x2 numbers.


7




OFFSET

1,1


COMMENTS

The 5tuple starting with 53542288800 was given by Donovan Johnson. The common value of sigma(x) is 294821130240.
A larger 5tuple, (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 ktuples, cf. link to MathWorld.


LINKS

Table of n, a(n) for n=1..9.
John Cerkan, More terms, with gaps.
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 MathWorldA Wolfram Web Resource.


CROSSREFS

Cf. A233553, A273928, A273931, A273933, A273934, A273936 (5tuples).
Cf. A036471  A036474 and A116148 (quadruples).
Cf. A125490  A125492 and A137231 (triples).
Sequence in context: A295042 A320880 A015401 * A273931 A273933 A196753
Adjacent sequences: A273927 A273928 A273929 * A273931 A273932 A273933


KEYWORD

nonn,more


AUTHOR

John Cerkan, Jun 04 2016


STATUS

approved



