[seqfan] Re: conjectured list of divisibility sequences

Matthew Vandermast ghodges14 at comcast.net
Sat Jan 8 20:58:17 CET 2011


> http://www.strw.leidenuniv.nl/~mathar/progs/oeisDivseq.html
 
Thanks for making this list!

Many divisibility sequences with the property that a(n) always divides a(n+1) have less than 30 "visible" entries in the database. Would it be worthwhile to do a separate computer search for sequences with this property?  This way, the minimum number of terms could be lowered from 30 while still keeping the number of false positives low.

Here are a few of these sequences, with the number of displayed terms (excluding b-files) in the database.   
 
A000142 21 terms (indices 0-20)
A002110 18 terms (0-17)
A002201 21 terms (1-21)
A003418 29 terms (0-28)
A004490 22 terms (1-22)
A006939 13 terms (0-12)
A051451 21 terms (1-21)
A111059 19 terms (1-19)
A181555 9 terms (0-8)

A182856 7 terms (0-6)
Best,
Matt Vandermast


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