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A192493
Numerators of squared radii of circumcircles of non-degenerate triangles with integer vertex coordinates.
12
1, 1, 5, 25, 25, 2, 5, 25, 25, 13, 325, 169, 65, 4, 65, 17, 425, 221, 9, 289, 1105, 169, 85, 5, 325, 85, 50, 1105, 289, 25, 2125, 625, 13, 325, 425, 1625, 169, 1105, 125, 65, 29, 2465, 4225, 1885, 725, 377, 2465, 5525, 1885, 125, 8, 145, 65, 841, 17, 841, 845, 425, 2125, 221, 6409, 9425, 9, 325, 289, 145, 1105, 37, 5365, 3145, 169, 2405, 925, 85, 1369, 4625, 481, 625, 493, 2405, 10
OFFSET
1,3
LINKS
Hugo Pfoertner, Table of n, a(n) for n = 1..9089, covering range R^2 <= 100.
Hugo Pfoertner, Circles Passing through 3 Points of the Square Lattice, illustrations up to R^2=10.
EXAMPLE
The smallest triangle of lattice points {(0,0),(1,0),(0,1)} has circumradius R=sqrt(2)/2, i.e., R^2=1/2. Therefore a(1)=1, A192494(1)=2.
CROSSREFS
Cf. A192494 (corresponding denominators), A128006, A128007.
Sequence in context: A036139 A070382 A271379 * A265973 A265928 A039936
KEYWORD
nonn,frac
AUTHOR
Hugo Pfoertner, Jul 10 2011
STATUS
approved