# Should OEIS links be updated?

Historic links to the OEIS are of the form http://www.research.att.com/~njas/sequences/A097048. These links no longer work: Neil has retired from AT&T, and in the meantime has set up the OEIS foundation. The working form these days is http://oeis.org/A097048.

Should the old-form links be changed by some automated process, or should it be left to individuals to update their links as they find them? I don't know if there's a generic policy for broken links, and I don't know, even if there is one, if the same logic should apply to the general case as to this one - an important resource for which the link pattern has changed in a predictable (and hopefully final) manner.

(I noted this when revisiting the comments for What's the simplest rational not expressible as a sum of a given number of unit fractions?, but I assume there are numerous similar references on mathoverflow.)

Hugo van der Sanden

• The example you point out is in a comment (of mine), and my understanding is that only moderators can edit comments. – Gerry Myerson Oct 28 '13 at 3:14
• Could Stack Exchange staff have these all automatically fixed? – Jonas Meyer Oct 28 '13 at 13:56
• I think that when we moved to 2.0 we gained the power to edit our own comments. Not sure if we can edit old comments of ours from before the migration, though. At least, I can't see how to do it. – David White Oct 28 '13 at 15:15
• @David: Nonmoderators can only edit comments within 5 minutes of posting them. – Jonas Meyer Oct 28 '13 at 15:16
• Okay, good to know. Thanks – David White Oct 28 '13 at 15:17

For reference, here are the pages that Google knows use the old domain.

If people have strong feelings, they can fix those they want to and remove them from this list. For comments, a follow-up comment pointing out the new url will probably be sufficient.

# Done

https://mathoverflow.net/a/28601/

https://mathoverflow.net/a/6408/

https://mathoverflow.net/a/30370/

https://mathoverflow.net/a/18639/ (and comment Number of invertible {0,1} real matrices?)

https://mathoverflow.net/a/42982/

https://mathoverflow.net/a/8503/

https://mathoverflow.net/a/8086/

https://mathoverflow.net/a/28488/

https://mathoverflow.net/a/44553/

Can a positive binary quadratic form represent 14 consecutive numbers?

https://mathoverflow.net/a/30371

https://mathoverflow.net/a/26639/

https://mathoverflow.net/a/29587/

### Not OEIS, but still links to Slaone's AT & T homepage

https://mathoverflow.net/a/78938/

https://mathoverflow.net/a/24865/

### Same, but in commeants

Prove: if a1,...,an are uniformly distributed unit vectors, then a1*a1'+...+an*an'=n/2*I (should be to http://neilsloane.com/sphdesigns/) How small can a sum of a few roots of unity be? (should be to http://neilsloane.com/doc/1218anti.ps)

• Feeling obsessive compulsive, I did most of the comments. – Scott Morrison Oct 28 '13 at 5:24
• You think you were obsessive-compulsive? I used the 'share' link on each question/answer to get the above list, manually (and trimmed the comments to links to short-form) ... ^_^ – David Roberts Oct 28 '13 at 6:17
• And I moved the others under the correct heading (wasn't looking close enough when I pasted those ones in). – David Roberts Oct 28 '13 at 6:20
• @Scott more for you... – David Roberts Oct 28 '13 at 6:22
• Thanks for the list - I'd guessed there would be more, but for these numbers I guess hand-editing is fine (accepting some "omg, something changed" front-page churn). – Hugo van der Sanden Oct 28 '13 at 19:32
• The striked ones are flooding the list? Could I remove them?. – Abhimanyu Pallavi Sudhir Oct 29 '13 at 12:08
• I moved the struck out ones down the page. @ScottMorrison - there are still four comments that need editing, if you feel so inclined. – David Roberts Oct 29 '13 at 22:26
• @DImension10AbhimanyuPS - I changed the WayBack machine links that you inserted to arxiv/neilsloane.com links. – David Roberts Oct 29 '13 at 22:46
• I also tracked down the other links to non-OEIS pages that need to be inserted into comments. – David Roberts Oct 29 '13 at 22:47
• @ScottMorrison - thanks! – David Roberts Oct 30 '13 at 3:12
• I found one of my questions with a link to Sloane's AT&T page that was not listed above. mathoverflow.net/questions/18636/… I edited it in. Can someone explain how they are searching for the culprits? – Tony Huynh Oct 30 '13 at 16:05
• @Tony Huynh: I fixed the answer, but there is still a comment. A pure speculation, but one reason the search might have missed it is that the link didn’t use markdown syntax, but HTML <a>...</a>. If so, there may be more such cases. – Emil Jeřábek Oct 30 '13 at 18:31
• You can probably get Scott Morrison's help to make an SQL query on the data explorer to find most occurrences. Gerhard "Or Grep A Database Dump" Paseman, 2013.10.30 – Gerhard Paseman Oct 30 '13 at 23:47
• "Grep a database dump" sounds vaguely sinister, or at the very least quite unsanitary. – Gerry Myerson Oct 31 '13 at 6:30
• @ScottMorrison: A quick google search using the term site:mathoverflow.net njas still seems to give comments whose links are broken e.g. mathoverflow.net/q/36188/16302 and mathoverflow.net/q/16780/16302. – jeq Nov 10 '13 at 21:49