[seqfan] Re: easy and bref
Charles Greathouse
charles.greathouse at case.edu
Fri Sep 30 18:33:15 CEST 2011
> Interesting. My understanding of "hard" was just the opposite: that it
> should be used when it is known that calculating more terms is hard, but not
> when there might be an easier way to make the calculation, but none such is
> known.
I'm not sure when that would ever apply. Would you give some examples?
Charles Greathouse
Analyst/Programmer
Case Western Reserve University
On Fri, Sep 30, 2011 at 12:15 PM, <franktaw at netscape.net> wrote:
> Interesting. My understanding of "hard" was just the opposite: that it
> should be used when it is known that calculating more terms is hard, but not
> when there might be an easier way to make the calculation, but none such is
> known.
>
> Franklin T. Adams-Watters
>
> -----Original Message-----
> From: Charles Greathouse <charles.greathouse at case.edu>
>
>> While "more" and "unkn" may be accompanied by "hard", "hard" does not
>> specify whether the difficulty is computational or analytical.
>
> I discuss this at
> https://oeis.org/wiki/User:Charles_R_Greathouse_IV/Keywords/easy_and_hard
> Increasingly, the keyword is being used not only for sequences where
> "it's not known" how to find more terms (getting another would be
> worth publishing a paper), but also for sequences where it's merely
> difficult to find more terms, even if the process itself is
> straightforward.
>
> Charles Greathouse
> Analyst/Programmer
> Case Western Reserve University
>
> On Thu, Sep 29, 2011 at 11:18 PM, Donald Alan Morrison
> <donmorrison at gmail.com> wrote:
>>
>> Some points of confusion in keywords (perhaps already mentioned
>
> before):
>>
>> While "more" and "unkn" may be accompanied by "hard", "hard" does not
>> specify whether the difficulty is computational or analytical. "fini"
>> is helpful of course. Maybe a new keyword like "comphard" would be
>> useful.
>>
>> "word" can intersect any of "uned"/"new"/"obsc" which seem redundant
>> (among themselves).
>>
>> On Thu, Sep 29, 2011 at 7:16 PM, Alonso Del Arte
>> <alonso.delarte at gmail.com> wrote:
>>>
>>> Those who know French or Latin might be able to help with some
>
> sequences
>>>
>>> having keywords easy, more and word. Yesterday I knocked more off
>
> such a
>>>
>>> sequence dealing with Portuguese (even though I don't know
>
> Portuguese)
>>>
>>> because it seemed to me that given how big the terms presently in the
>>> sequence are, larger terms would run into questions of non-standard
>
> names
>>>
>>> for larger numbers.
>>>
>>> Al
>>>
>>> On Thu, Sep 29, 2011 at 8:32 PM, Charles Greathouse <
>>> charles.greathouse at case.edu> wrote:
>>>
>>>> I encourage people to remove the "easy" keyword from sequences that
>>>> don't deserve it (and to add it to those that need it, of course).
>
> If
>>>>
>>>> you can't even make a thousand-term b-file it's probably not easy
>>>> (unless the terms are just too big to fit).
>>>>
>>>> Charles Greathouse
>>>> Analyst/Programmer
>>>> Case Western Reserve University
>>>>
>>>> On Thu, Sep 29, 2011 at 7:38 PM, Joseph S. Myers
>
> <jsm at polyomino.org.uk>
>>>>
>>>> wrote:
>>>> > On Mon, 26 Sep 2011, Nathaniel Johnston wrote:
>>>> >
>>>> >> Dear SeqFans,
>>>> >>
>>>> >> Another keyword combination that is quite ugly to my eye is
>
> "easy" and
>>>>
>>>> >> "more". I've cleaned up quite a few of these by adding more
>
> terms, but
>>>>
>>>> there
>>>> >> are still 291 remaining. Most of these sequences still contain
>
> both
>>>>
>>>> keywords
>>>> >> for one of two reasons: either the sequence is difficult to
>
> understand
>>>>
>>>> >> and/or needs editing by someone with expertise in the area (such
>
> as
>>>>
>>>> >> A002875), or it is "easy" to construct small terms by hand but
>
> writing a
>>>>
>>>> >> program to compute terms seems to be a nontrivial task (such as
>>>> A072149).
>>>> >
>>>> > I've submitted extensions and b-files for A072149-A072151 - they
>
> aren't
>>>>
>>>> > that hard to program; A072152-A072154 to follow later. I haven't
>
> tried
>>>>
>>>> to
>>>> > determine their generating functions, though they will certainly
>
> have
>>>>
>>>> > rational generating functions.
>>>> >
>>>> > There are 238 easy+more sequences left - I think most are probably
>>>> > genuinely easy once you've understood them (which is the
>
> nontrivial part
>>>>
>>>> > in many cases). Some look "easy" to add a few more terms to but
>
> not to
>>>>
>>>> > extend to the full three rows let alone to 1000 terms in a b-file
>>>> > (A092645, for example). It might be interesting to see what
>
> "easy"
>>>>
>>>> > sequences there are that are significantly short of the normal
>
> three rows
>>>>
>>>> > of numbers but aren't marked "more" (more generally, if a
>
> sequence is
>>>>
>>>> well
>>>> > short of three rows of numbers but isn't "full", it's a candidate
>
> for
>>>>
>>>> > "more" unless it's known the next number would take it over three
>
> rows).
>>>>
>>>> >
>>>> > --
>>>> > Joseph S. Myers
>>>> > jsm at polyomino.org.uk
>>>> >
>>>> > _______________________________________________
>>>> >
>>>> > Seqfan Mailing list - http://list.seqfan.eu/
>>>> >
>>>>
>>>> _______________________________________________
>>>>
>>>> Seqfan Mailing list - http://list.seqfan.eu/
>>>>
>>>
>>>
>>>
>>> --
>>> Alonso del Arte
>>> Author at
>
> SmashWords.com<https://www.smashwords.com/profile/view/AlonsoDelarte>
>>>
>>> Musician at ReverbNation.com
>
> <http://www.reverbnation.com/alonsodelarte>
>>>
>>> _______________________________________________
>>>
>>> Seqfan Mailing list - http://list.seqfan.eu/
>>>
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>
>
> _______________________________________________
>
> Seqfan Mailing list - http://list.seqfan.eu/
>
More information about the SeqFan
mailing list