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URL: https://oeis.org/A164014

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A164014
Numbers n for which the Hurwitz equation (x_1)^2 + (x_2)^2 + ... + (x_n)^2 = z * x_1 * x_2 * ... * x_n has solutions only for z = n.
4
12, 24, 32, 48, 60, 108, 240, 384, 480, 608, 972, 984, 1020, 2688
OFFSET
1,1
COMMENTS
Conjectured finite. Any further terms are greater than 10^8.
LINKS
A. Hurwitz, Über eine Aufgabe der unbestimmten Analysis, Archiv der Mathematik und Physik 11 (1907) pp. 185-196.
Norman P. Herzberg, On a problem of Hurwitz, Pacific Journal of Mathematics 50 (1974), pp. 485-493.
Ioulia Baoulina and Florian Luca, On positive integers with a certain nondivisibility property, Annales Mathematicae et Informaticae 35 (2008), pp. 11-19.
CROSSREFS
Sequence in context: A103590 A081699 A120570 * A336772 A098113 A172415
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
Definition corrected by Max Alekseyev, Nov 13 2012
STATUS
approved