A set $S$ of integers is Balearic, if there are two (not necessarily distinct) elements $s,s'\in S$ whose sum $s+s'$ is a power of two; otherwise it is called a non-Balearic set. Find an integer $n$ such that $\{1,2,\ldots,n\}$ contains a 99-element non-Balearic set, whereas all the 100-element subsets are Balearic.
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Tags: combinatorics, number theory
socrates
15.06.2017 14:40
In fact, we can find all such $n.$
Borbas
07.03.2018 19:24
Bump bump
ythomashu
07.03.2018 19:27
Mediterranean MO 2017 #3
ythomashu
07.03.2018 19:50
A091067 is non-Balearic.
ythomashu
07.03.2018 20:03
$n\in[a(100),a(101))\cap\mathbb{Z}$
Borbas
08.03.2018 17:11
Yet you need to prove that each subset $B$ of $\{1,2,...,a(100)\}$ such that $|B|=100$ is Balearic
ythomashu
08.03.2018 17:19
http://oeis.org/A060833 Quote: a(1) = 1; and for n > 1: a(n) = A091067(n-1)+1.