OFFSET
1,1
REFERENCES
D. A. Buell, Binary Quadratic Forms, Springer-Verlag, NY, 1989, pp. 92-93.
Paulo Ribenboim, My Numbers, My Friends: Popular Lectures on Number Theory, Springer-Verlag, NY, 2000, p. 151.
PROG
(PARI) isok(D) = isfundamental(D) && norm(quadunit(D))==1;
CROSSREFS
KEYWORD
nonn
AUTHOR
Arkadiusz Wesolowski, Nov 23 2021
STATUS
approved