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A289972
Number of sets S (cubic acute n-set), with cardinality A089676(n) >= 3, of points in {0,1}^n in real n-dimensional Euclidean space such that every angle determined by three distinct points in S is acute.
2
0, 0, 2, 16, 352, 240, 107520, 1032837120
OFFSET
1,3
COMMENTS
Consider the 2^n points {0,1}^n in real Euclidean space. Then A089676(n) = maximal size of a subset S of these 2^n points such that there is no triple of points P,Q,R in S which subtends a right angle. That is, we are not allowed to have P-Q perpendicular to R-Q. Here we count such sets.
LINKS
D. Bevan, Sets of Points Determining Only Acute Angles and Some Related Coloring Problems, Electronic J. of Combinatorics, 13(1), 2006, #R12.
Fausto A. C. Cariboni, Complete solutions for a(3)-a(6)
Fausto A. C. Cariboni, Complete solutions for a(7)
CROSSREFS
Cf. A089676.
Sequence in context: A012610 A012721 A297095 * A179472 A009341 A366396
KEYWORD
nonn,hard,more
AUTHOR
STATUS
approved