Let d be a squarefree integer and consider the subclass of primes with Legendre symbol ( d/p ) = +1. It is shown that for x large enough (x; 2x] contain a prime of this type.
@article{15138, title = {A Bertrand postulate for a subclass of primes}, journal = {Boletim da Sociedade Paranaense de Matem\'atica}, volume = {31}, year = {2013}, doi = {10.5269/bspm.v31i2.15138}, language = {EN}, url = {http://dml.mathdoc.fr/item/15138} }
Reddy, G. Sudhaamsh Mohan; Rau, S. Srinivas; Uma, Bidarahalli. A Bertrand postulate for a subclass of primes. Boletim da Sociedade Paranaense de Matemática, Tome 31 (2013) . doi : 10.5269/bspm.v31i2.15138. http://gdmltest.u-ga.fr/item/15138/