[seqfan] Re: easy and bref

franktaw at netscape.net franktaw at netscape.net
Fri Sep 30 18:15:58 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.

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/
>

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