# [seqfan] Re: Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v

Richard Guy rkg at cpsc.ucalgary.ca
Sun Nov 23 17:58:35 CET 2008

```Neil & others,
This discovery prompted me to look up
amicable triples & quadruples in OEIS.  For the former,
I found x, y, z, in A125490,1,2, but didn't find x+y+z.

For the latter, there's some confusion,
A036471,2,3,4  shd be a,b,c,d and A116148 a+b+c+d,
but there seems to be something wrong with the statements.

Best to all,   R.

On Sun, 23 Nov 2008, koh wrote:

>    Dear Seqfans
>
>    I submitted Amicable 5-ple sequence.
>    It is the first known example.
>    More term  are wanted.
>
>
>
>    %I A000001
>    %S A000001 227491164588441600
>    %N A000001 5-ple x,y,z,u,v such that Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v
>               Sequence gives the smallest element.
>    %C A000001 Resta computed up to 10^7, but no example exists.
>    %Y A000001 A000002,A000003,A000004,A000005
>    %K A000001 none
>    %O A000001 1,1
>    %A A000001 Yasutoshi Kohmoto   zbi74583.boat at orange.zero.jp
>
>
>    %I A000002
>    %S A000002 228507506351308800
>    %N A000002 5-ple x,y,z,u,v such that Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v
>               Sequence gives second smaller element.
>    %Y A000002 A000001,A000003,A000004,A000005
>    %K A000002 none
>    %O A000002 1,1
>    %A A000002 Yasutoshi Kohmoto   zbi74583.boat at orange.zero.jp
>
>
>    %I A000003
>    %S A000003 229862628701798400
>    %N A000003 5-ple x,y,z,u,v such that Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v
>               Sequence gives 3rd smaller element.
>    %Y A000003 A000001,A000002,A000004,A000005
>    %K A000003 none
>    %O A000003 1,1
>    %A A000003 Yasutoshi Kohmoto   zbi74583.boat at orange.zero.jp
>
>
>    %I A000004
>    %S A000004 230878970464665600
>    %N A000004 5-ple x,y,z,u,v such that Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v
>               Sequence gives 4th smaller element.
>    %Y A000004 A000001,A000002,A000003,A000005
>    %K A000004 none
>    %O A000004 1,1
>    %A A000004 Yasutoshi Kohmoto   zbi74583.boat at orange.zero.jp
>
>
>    %I A000005
>    %S A000005 243752632794316800
>    %N A000005 5-ple x,y,z,u,v such that Sigma(x)=Sigma(y)=Sigma(z)=Sigma(u)=Sigma(v)=x+y+z+u+v
>               Sequence gives the largest element.
>    %Y A000005 A000001,A000002,A000003,A000004
>    %K A000005 none
>    %O A000005 1,1
>    %A A000005 Yasutoshi Kohmoto   zbi74583.boat at orange.zero.jp
>
>
>
>    Yasutoshi
>
>
>
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>
>
>

```