[seqfan] Re: 3-sequences relations using Robert Gerbicz's seeker.c

Georgi Guninski guninski at guninski.com
Tue Aug 24 11:42:21 CEST 2010

On Mon, Aug 23, 2010 at 10:01:29PM -0400, Charles Greathouse wrote:
> That does sound interesting.  But I think it's infeasible for other
> reasons: the human time needed to sift through the resulting
> sequences.
> If (extrapolating) there are a million 3-sequence relationships
> between 200,000 sequences, then we'd expect to the order of a hundred
> million 4-sequence relationships between 200,000 sequences.
> In fact, even just the 3-sequence relations seem hard to analyze. If
> there are 500 active SeqFans members (surely an overestimate) then
> each would need to check 2000 sequence relations.  Perhaps half would
> be trivial and anther quarter could be dismissed without much work,
> but that's still 500 difficult relations per person.  50 I could
> imagine; 500 would be too many to ask.  50,000 seems entirely more
> than a person could reasonably check.
> Charles Greathouse
> Analyst/Programmer
> Case Western Reserve University

Charles, i agree with you.

the post was just a computational experiment, i don't claim it makes any sense or is interesting/worth.

some marginal benefits of the test may be:

1. the experiment was just a toy experiment based on too little number of terms. if instead of 30 terms 100 terms were used the # of relations would be considerably smaller imo. try searching for the integers 1 .. 30 and 1 .. 45 in oeis. (126 vs 67). btw, the choice of just 30 terms may be a big mistake of mine.

to play devil's advocate, the oeis may genuinely contain an enormous number of inter-relations that is infeasible for the humans on seqfan, so what ;)

2. i suppose most people are not interested in *all* sequences, they are *particularly* interested in a small subset of them. so if someone is doing a web search for a sequence or a pair of sequences he may find the list of potential relations and ideally find a nontrivial relation by examining them (that's the main reason i posted a large list. it happened to me when doing web search ironically to end up on my site - the search results were < 10)

3. a new computer program may prune the large number of relations e.g. by verifying them to the max available terms or deleting trivially related (by definition) sequences.

More information about the SeqFan mailing list