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UID:www.tcs.tifr.res.in/event/722
DTSTAMP:20230914T125935Z
SUMMARY:Permutations Avoiding Arithmetic Progressions
DESCRIPTION:Speaker: Phani Raj Lolakapuri\n\nAbstract: \nIn 1977\, J.A. Dav
is et al showed that any finite subset of natural numbers can be permuted
such that it does not contain any 3-term A.P. as a sub-sequence. However\,
this is not true for the set of all natural numbers. Furthermore\, they a
lso show that there exists a permutation of natural numbers which does not
contain any 5-term A.P. as a sub-sequence.\nGeneralizing this\, we say th
at a subset of natural numbers is k-avoidable if there exists a permutatio
n of the elements of the set which does not contain any k-term A.P. as a s
ub-sequence. In 2008\, LeSaulnier and S. Vijay gave bounds on the densitie
s of subsets of natural numbers which are 3-avoidable and 4-avoidable. In
this talk\, I will discuss my contribution (in collaboration with S. Vijay
) to this work\, which was an improvement over these bounds.\n
URL:https://www.tcs.tifr.res.in/web/events/722
DTSTART;TZID=Asia/Kolkata:20161111T160000
DTEND;TZID=Asia/Kolkata:20161111T173000
LOCATION:A-201 (STCS Seminar Room)
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