%I #20 May 29 2016 01:46:53
%S 1,2,3,7,11
%N Values of D for which the imaginary quadratic field Q[ sqrt(-D) ] is norm-Euclidean.
%C Hardy & Wright's Theorem 246: "There are just five complex Euclidean quadratic fields, viz., ... ."
%D P. M. Cohn, On the structure of the GL2 of a ring, Publ. Math. Inst. Hautes Etudes Sci., 30 (1966), 5-53.
%D G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers. 5th ed., Oxford Univ. Press, 1979, p. 213.
%H Bogdan Nica, <a href="http://www.jstor.org/stable/10.4169/amer.math.monthly.118.05.455">The Unreasonable Slightness of E2 over Imaginary Quadratic Rings</a>, Amer. Math. Monthly, 118 (2011), 455-462.
%H Arseniy Sheydvasser, <a href="http://dx.doi.org/10.4169/amer.math.monthly.123.5.482">A Corrigendum to Unreasonable Slightness</a>, Amer. Math. Monthly, 123 (2016), 482-485.
%F a(n) = A003173(n) = -A048981(6-n) for n = 1, 2, 3, 4, 5.
%Y Cf. A003173, A003174, A048981.
%K nonn,fini,full
%O 1,2
%A _Jonathan Sondow_, Oct 19 2015