Comment for A000384

[Charles Marion]

Dear Seqfans,

 

I am submitting the following comment for A000384

 

It is well known that for n>0, A014105(n) [0,3,10,21,...] is the first of
2n+1 consecutive integers such that the sum of the squares of the first n+1
such integers is equal to the sum of the squares of the last n; e.g.,
10^2+11^2+12^2=13^2+14^2.

 

Less well known is that for n>1, a(n) [0,1,6,15,28... ] is the first of 2n
consecutive integers such that sum of the squares of the first n such
integers is equal to the sum of the squares of the last n-1 plus n^2; e.g.,
15^2+16^2+17^2=19^2+20^2+3^2.

 

Can anyone supply a reference to the latter identity?

 

Thanks.

 

Charlie Marion   

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.seqfan.eu/pipermail/seqfan/attachments/20061216/945b619a/attachment-0001.htm>