On Ono's problem on quadratic fields (Q1185154)

Let \(m\) be a squarefree integer, \(k=\mathbb{Q}(\sqrt{m})\), \(\chi_ k=\) Kronecker character for \(k\), and \(M_ k=\) Minkowski constant for \(k\). The set \(K^ +\) is defined to be the set of all \(k\)'s such that \(\chi_ k(p)=+1\) for all rational primes \(p\leq M_ k\). The authors show that \[ K^ +=\{k=\mathbb{Q}(\sqrt{m})\mid m=-1,\pm 2,\pm 3,5,-7,13,-15,17,-23,33,- 47,-71,73,97,-119\}. \]