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 A208952 Number of distinct values of the areas of the convex hulls of permutations {(1,p(1)), (2,p(2)), ..., (n,p(n))} of {1, 2, ..., n}, considered as points in the plane. 1
 1, 1, 2, 5, 11, 24, 39, 60 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE For n=3, the two permutations (sets of points) {(1,1),(2,2),(3,3)} and {(1,3),(2,2),3,1)} have a convex hull with zero area, whereas the remaining four permutations {(1,1),(2,3),(3,2)}, {(1,2),(2,1),(3,3)}, {(1,2),(2,3),(3,1)}, and {(1,3),(2,1),(3,2)} each have a convex hull with area 3/2.  Thus there are two distinct values of the areas, so a(3)=2. MATHEMATICA (* v. 8.0*) <

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Last modified January 23 13:57 EST 2022. Contains 350511 sequences. (Running on oeis4.)