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A322742
Sorted list of 120 distinct triangle areas corresponding to the unique solution to the problem of placing 10 points on a grid rectangle of minimal area, such that all triangles formed by any 3 of the points have distinct areas > 0.
3
1, 2, 3, 4, 7, 8, 9, 14, 15, 19, 20, 21, 23, 24, 26, 27, 28, 30, 31, 33, 34, 35, 36, 37, 39, 40, 42, 43, 45, 46, 47, 49, 50, 52, 53, 55, 56, 58, 59, 61, 65, 67, 68, 69, 70, 74, 75, 77, 78, 79, 80, 81, 84, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 100, 101, 106, 107, 111
OFFSET
1,2
COMMENTS
The sequence gives the areas multiplied by 2.
For more information see A322740.
The coordinates of the 10 grid points on the minimal 19 X 18 rectangle are (0,3), (1,9), (2,18), (5,0), (5,10), (12,17), (15,13), (17,4), (18,0), (19,5).
LINKS
PROG
(PARI) X=[0, 1, 2, 5, 5, 12, 15, 17, 18, 19]; Y=[3, 9, 18, 0, 10, 17, 13, 4, 0, 5]; n=0; a=vector(binomial(#X, 3)); for(i=1, #X-2, for(j=i+1, #X-1, for(k=j+1, #X, a[n++]=X[i]*(Y[j]-Y[k])+X[j]*(Y[k]-Y[i])+X[k]*(Y[i]-Y[j]))))
vecsort(abs(a))
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Hugo Pfoertner, Dec 24 2018
STATUS
approved