Erel Segal-Halevi
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 Apr 23 awarded Yearling Apr 17 accepted Is there always a way to pick a card from each number? Apr 14 comment Is there always a way to pick a card from each number? Thanks! Why is it $(k-1)$? Shouldn't it be $k$ = the number of ways to pick $k-1$ rows out of $k$? Apr 14 revised Is there always a way to pick a card from each number? added 4 characters in body Apr 14 comment Creating a periodic sequence from a given subsequence @almagest I do not understand your last comment. Why can't you have uncountably many odd sequences completed to the same rational number? Apr 14 asked Is there always a way to pick a card from each number? Apr 14 asked Creating a periodic sequence from a given subsequence Apr 10 asked If $n={k^2 \choose k}$, then what is $k$? Apr 10 accepted A combinatorial card-trick Apr 8 comment A combinatorial card-trick Thanks! Are there any more sophisticated variants of this trick? Apr 8 asked A combinatorial card-trick Apr 8 revised Is $x^x=y$ solvable for $x$? Add asymptotic expression Mar 27 comment Shrinking some polygons to make the containing polygon connected @Moti this is interesting. I would really like that the path has some width, but I am not sure how to define this accurately. Mar 27 asked Shrinking some polygons to make the containing polygon connected Mar 21 accepted Connectivity with minimal width Mar 21 revised Connectivity with minimal width added 97 characters in body Mar 21 asked Connectivity with minimal width Mar 7 comment Number of orderings of subset sums @Mad but what if we allow $x$ to be negative? Then, $x$ starts at minus infinity and goes to infinity. Mar 7 comment Number of orderings of subset sums Nice idea! But I do not understand the details. Suppose we allow negative numbers. Then, each spike from the lower axis passes $2^k$ spikes from the upper axis, so the final result should be $f(k)\cdot (2^k)^2$. Feb 15 accepted The rectangle-partition number and the number of horizontral edges