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A128010 Numerators of rational-valued radii of circles given by 3 distinct integer points in the 4-dimensional Euclidean space. 6
1, 5, 3, 5, 7, 11, 2, 17, 13, 9, 7, 33, 19, 5, 13, 21, 27, 11, 14, 17, 29, 3, 37, 31, 25, 19, 13, 33, 10, 27, 17, 41, 7, 25, 18, 29, 51, 11, 37, 26, 15, 53, 19, 99, 65, 23, 27, 39, 47, 55, 91, 4, 65, 57, 49, 41, 33, 29, 25, 67, 21, 59, 17, 30, 43, 69, 13, 61, 35, 22, 53, 31, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A triangle in the 4-dimensional Euclidean space defines a circumcircle. There exist only certain rational-valued circumradii if the vertices of the triangle have integer coordinates. They are listed by the pair of sequences A128010/A128011 in increasing order.

LINKS

Table of n, a(n) for n=1..73.

CROSSREFS

See A128011 for denominators. Cf. A128006, A128007, A128008, A128009.

Sequence in context: A269893 A336055 A131925 * A185046 A114740 A330523

Adjacent sequences:  A128007 A128008 A128009 * A128011 A128012 A128013

KEYWORD

frac,nonn

AUTHOR

Heinrich Ludwig, Feb 18 2007

STATUS

approved

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Last modified June 13 22:55 EDT 2021. Contains 345016 sequences. (Running on oeis4.)