Difference

[franktaw at netscape.net]

You need to improve the definition.  I would interpret this as a(9) = 3 
- 1 = 2.  Apparently, you want to always include the number itself in 
the difference - apparently again, allowing it to be there with either 
sign.  Do you want to allow a(70) = 70 + 2 - 1 - 5 - 7 - 10 - 14 - 35 = 
0?

You should also include cross-references to A005835 and A023196.

Are there any abundant numbers for which the sequence is not zero 
(assuming defined as above such that a(70) = 0)?  Any such numbers 
would have to be weird numbers (A006037), and the smallest such would 
have to be a primitive weird number (A002975) - which means it must be 
at least 836.

Franklin T. Adams-Watters


-----Original Message-----
From: zbi74583 at boat.zero.ad.jp

...
    %I A000001
    %S A000001 1,1,2,1,4,0,6,1,5,2,10,0
    %N A000001 The smallest difference of divisors of n.
    %C A000001 If a(n)=p then a(n)=p-1. If a(n)=2^m then a(n)=1
    %e A000001 a(6)=1+2+3-6=0
...

    Yasutoshi



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I believe a comment to the OEIS is the standard way to publish  
results like this. I think most people who are interested in such  
matters have learned that OEIS is a good place to find them. I don't  
know of any journals that would be interested.

Regards,
David

On Jan 10, 2007, at 5:27 PM, Tanya Khovanova wrote:

> Hello seqfans,
>
> I've noticed (and proved) that the number of 01-avoiding words of  
> length n on alphabet {0,1,2,3, ..., d} which do not end in 0 can be  
> easily described. The sequence starts with 1, d and follows the  
> recursion a(n) = (d+1)*a(n-1) - a(n-2).
>
> I am submitting this comment to the relevant sequences.
>
> My question is - if this comment is not present in the sequences  
> should I assume that this is something new? If it is something new  
> what is the standard way to publish small results like this?
>
> Best, Tanya
>
>