Duplicate hunting

[franktaw at netscape.net]

The ones where the definition is not the same are also of interest.  
There are three possibilities:

1) Although the definitions are different, the actual sequences (out to 
infinity) are the same.  In this case, these are duplicates, and should 
be merged.
2) The sequences differ at some term beyond what is included in the 
database.  In this case, at least one - preferably both - should have a 
comment indicating where they differ.
3) We can't tell if the sequences are different or not.  In this case, 
they should reference each other with some sort of comment indicating 
that the equality of the sequences is unknown.

Franklin T. Adams-Watters


-----Original Message-----
From: aplewe at sbcglobal.net

   My mind is taking a bit of a break from other math pursuits, so I've 
decided in the down-time to find duplicate sequences in the OEIS. I 
have a text file of about 1500 sequences that match lexically (same 
values, same ordering) that I'm using, then manually comparing the 
sequences to see if they actually have the same definition. I'd be 
happy to share this file with anyone who'd like to participate, email 
me off-list and I'll send it along (approx. 280k text file). Anyways, 
here are a few that I've found this evening by working from the last 
line of the file upwards. If it's preferable, I'll send future 
duplicates to Neil directly or a designated editor/editors to keep 
traffic down on the email list.
 ...

 -Andrew Plewe-



________________________________________________________________________
Check Out the new free AIM(R) Mail -- 2 GB of storage and 
industry-leading spam and email virus protection.



I'm working on an enumeration sequence, and I find that in my calculations
I'm regularly needing recourse to two functions that I don't really know
how to write, which also makes it harder to think about them.

The first is a truncation function u(x):

The second is a similar v(x), with an exception at zero:

Is there standard notation and/or naming for either of these functions,
particularly such as would allow me to search for them and learn how
to do useful maths with them?

In case it helps, the domain of 'x' I'm interested in is the integers
in both cases.

HUgo