This site is supported by donations to The OEIS Foundation.

Things to do on the OEIS

From OeisWiki
(Redirected from To do on the OEIS)
Jump to: navigation, search
OEIS wants you: You can help!

[[{{fullurl:{{#urlencode:Things to do on the OEIS}}|action=edit&section=0}} Edit top section]]
This is a proposal for part of a "community portal", which would suggest (in a way parallel to some dedicated keywords as "more", "uned", ...) "small" things to be done on the main database [OEIS.org].

Such a portal, once accepted, could replace postings on the SeqFan list (and/or at least "collective answers" to the whole list), which probably do not interest a vast majority of the subscribers, and at the same time might serve as a place to organize work and to avoid duplicate efforts, if two "kind souls" decide at the same time that they could invest some of their time to fix this issue or another one.

These "job proposals" could be separated in "categories" as is tentatively done below using some section titles. It could be a good practice to put a short comment ("Taken. ~~~~") after the given entry, when you plan to work on it, and/or some other comment to be included in possible follow-up e-mails on that issue, etc.

Definitions to be reworded

Please post here links to sequences and appropriate additional information to request suggestions and/or help for improving sequence's definitions.

DONE in Feb.2013 by R. J. Mathar -- thanks!

Errors to correct

Please post here links to sequences and an appropriate comment when you are sure that there's an error somewhere but feel unable to fix it yourself right now.

  • ...

Probable errors

Please list here sequences & explanations when you think there is probably an error, but would like to have confirmation (and/or a fix) from someone else:

Computational help needed

Please list here sequences where you think it should be easy and/or interesting to add more terms and/or a program, and/or where you can give some ideas on how to do it, and similar cases:

  • Freestyle perfect numbers (It may be easier to compute the subsequence of those which have at most one single "spoof prime factor" which may further be assumed to be the largest one.)
  • URPMS : see link to seqfan post in seq. A145681. For 4/3: 3,45,1512,51408...; 5/4: 4,72,2448,3168,5824...; 6/5: 5,1323000...; 7/6: 216,7344,9504,26568...
(PARI): f=6/5;for(n=1,9e9,n*f==A034448(n)&&print1(","n))
  • code for A030272: Number of partitions of n^3 into unequal cubes, and neighbors. — M. F. Hasler 04:28, 19 February 2014 (UTC)

Other

(please specify)

"families" of sequences to be edited

zeroless powers
and (powers of...): ..., A195908, A195946, A195945 as well as A195942, A195943 and other related sequences should receive edits to make them more complete:
  • at least this list of xrefs, to be completed
  • The NAMES "Decimal expansion of x^n..." should be changed to "Numbers n such that ..."
  • PARI code (easily copy/pasted from one of the seq's where it is already put)
  • references to Primera's puzzle 607 and Schneider's web page stored as a local copy. — MFH 13:42, 7 March 2014 (UTC)
See the dedicated page zeroless powers for more information.
  • ...
Undulating numbers

Sequences A032841, ..., A032907 all are about undulating numbers (digits alternatingly increasing and decreasing) in various bases. They should xref each other or at least some "main entry".

"uned" sequences

Help is needed to edit the following sequences:

  • A157017: Numbers n such that n! can be written as a product of distinct factors in the range from n+1 to 2n, inclusive. There is only a finite number of terms in this sequence, attributed to Erdös. The explicit factorizations are shown for 1! ... 44!, which clutter the page; the longer ones should be written as f(x_1,...,x_k) where these x_i are the (few) factors missing in ((2n)!/n!)/(primorial(2n)/primorial(n)). — MFH 11:46, 26 February 2014 (UTC)

completing links

  • Look for LINKS to the Yahoo! group "primenumbers": many still lack "..., Yahoo! group "primenumbers", < Date >",   (with < Date > revealed upon clicking on the link): Work in progress, but you might help - Thanks! — M. F. Hasler 01:59, 17 February 2014 (UTC)
  • Similar to the above, there might be other "families" of links that should be updated (ill-formatted MathWorld links with no precise page title given,...).

Huge records

  • Some huge records such as A001622 (the golden ratio φ) or A000040 (the prime numbers) require to be edited and (before that) to establish a "policy" about restrictions of what to allow there. Quality of comments are difficult to judge, but for references/links, consensus about a rather "clear" policy could be reached. I suggest to discuss details on the page Talk:Things to do on the OEIS#Huge_records. — MFH 14:53, 24 February 2014 (UTC)
  • A157017: Numbers n such that n! can be written as a product of distinct factors in the range from n+1 to 2n, inclusive. There is only a finite number of terms in this sequence, attributed to Erdös. The explicit factorizations are shown for 1! ... 44!, which clutter the page; the longer ones should be written as f(x_1,...,x_k) where these x_i are the (few) factors missing in ((2n)!/n!)/(primorial(2n)/primorial(n)). — MFH 11:49, 26 February 2014 (UTC)
Retrieved from "https://oeis.org/w/index.php?title=Things_to_do_on_the_OEIS&oldid=1588706"