2 things about the OEIS Welcome Page

[Joerg Arndt]

To make it clear to the non-tech-freaks:

% wget -S http://www.jjj.de/
--12:23:17--  http://www.jjj.de/
           => `index.html'
Resolving www.jjj.de... 80.190.231.112
Connecting to www.jjj.de|80.190.231.112|:80... connected.
HTTP request sent, awaiting response... 
  HTTP/1.1 200 OK
  Date: Thu, 05 Jun 2008 10:18:52 GMT
  Server: Apache/2.2.8 (Linux/SUSE)
  Last-Modified: Tue, 08 Jan 2008 10:01:46 GMT   <--= *** there ***
  ETag: "edba-163f-44333107f1680"
  Accept-Ranges: bytes
  Content-Length: 5695
  Vary: Accept-Encoding
  Connection: close
  Content-Type: text/html; charset=ISO-8859-15
Length: 5,695 (5.6K) [text/html]

seqs in the OEIS have a static URL:

% wget -S http://www.research.att.com/~njas/sequences/A034548
--12:24:27--  http://www.research.att.com/~njas/sequences/A034548
           => `A034548'
Resolving www.research.att.com... 192.20.225.32
Connecting to www.research.att.com|192.20.225.32|:80... connected.
HTTP request sent, awaiting response... 
  HTTP/1.1 200 OK
  Date: Thu, 05 Jun 2008 10:20:15 GMT
  Server: Apache/2.0.52 (CentOS)
  Content-Type: text/html; charset=utf-8
  Connection: close
Length: unspecified [text/html]

I did not know this mechanism existed.  Nice!


* Brendan McKay <bdm at cs.anu.edu.au> [Jun 05. 2008 20:17]:
> The reason that "subscribe" and similar features do not work is that
> the ATT server does not include the Last-Modified: header in serving
> OEIS pages. This is not the case for all pages on that server,
> so maybe there is some way to do it. The best chance would be an
> ordinary URL (without the "?q..." stuff) for the raw text version of the sequence. Is there one?
> 
> Btw, since wget is mentioned I'll mention that "wget -S URL" is one
> way to see the HTTP headers.
> 
> Brendan.
> 
> * Joerg Arndt <arndt at jjj.de> [080605 18:24]:
> > 
> > A script that does a wget (of the internal format as text),
> > and diffs with the last version would also do the job.
> > E.g. see
> > http://www.research.att.com/~njas/sequences/?q=id%3aA111111&p=1&n=10&fmt=3
> > Only the first few and the last line would have to be discarded.
> > Like this:
> > 
> > wget URL | grep -A999 '^%I' | grep -B999 '^%A' > bla
> > diff bla bla-old && some-alert-func
> > 
> > People "subscribing" this way will create a load by
> > page polling.  However, when a poll is done reasonably rare
> > (e.g. once a day) there should be no problem.
> > 
> > 
> > * Jonathan Sondow <jsondow at alumni.princeton.edu> [Jun 05. 2008 17:43]:
> > > Neil,
> > > 
> > > Re subscribing to an OEIS entry:
> > > 
> > > I followed Maximilian's suggestion and used IE to subscribe to the text
> > > format of an OEIS entry. But I was often notified that the page had changed
> > > when only the time to create the page had changed. So I stopped subscribing.
> > > 
> > > Best,
> > > Jonathan
> > > 
> > > [...]