There are a few A058445 2236081408416666 A058446 5000060065066660656065066555556 A072288 316912650057057350374175801344000001 A076337 509203 A115453 1414213562373095048801688724209698078569671875376948073 A118329 9159655941772190150546035149323841107741493742816721 A122036 351351 A144134 62527434837271029229 A230528 375494703 A245206 1019 but generally we require 3+ terms. Charles Greathouse Case Western Reserve University On Mon, Jun 6, 2016 at 9:20 AM, Veit Elser <ve10@cornell.edu> wrote:
On Jun 6, 2016, at 7:38 AM, Dan Asimov <asimov@msri.org> wrote:
An old geometry problem discussed here asks for a finite set of points in the plane such that the perpendicular bisector of any 2 of the points contains exactly 2 of the points.
At last check there was just one known solution (up to rotation and scaling). In case anyone feels like looking for a solution, I won't mention the answer unless asked to.
Are there entries in OEIS that have just one integer, as in “number of points in known solutions to Dan’s problem”? You would have to add terms such as “bisector” to search such items.
-Veit _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun