[seqfan] Re: A094627: Sequence whose n-th term digits sum to 2n+1.

Joerg Arndt arndt at jjj.de
Mon Nov 15 09:41:54 CET 2010


* Charles Greathouse <charles.greathouse at case.edu> [Nov 15. 2010 08:16]:
> I don't understand the definition of A094627.  The (decimal) digit sum
> of a(n) is indeed 2n+1, but it's not clear to me how one is chosen.
> There is a generating function, but that's not a part of the
> definition in this case, and of course it would be good to check that
> it is actually correct.

Looks OK:
(x^2 + 2*x + 1)/(10*x^3 - 10*x^2 - x + 1)
? (1+x)^2/((1-x)*(1-10*x^2))+O(x^33)
1 + 3*x + 14*x^2 + 34*x^3 + 144*x^4 + 344*x^5 + 1444*x^6 + 3444*x^7 + 14444*x^8 + ...

I wish people would use '*' where it belongs.

The choice seems arbitrary and
IMHO the sequence is not interesting.


> 
> If someone has a better idea of what it means, please edit it.  Also,
> add keyword:base.
> 
> Charles Greathouse
> Analyst/Programmer
> Case Western Reserve University
> 
> 
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