OFFSET
1,2
COMMENTS
EXAMPLE
42 is in this sequence because sqrt(42) = 6.480740..., and -42 is quadratic nonresidue mod all odd primes < 6.480740... not dividing 42 (only mod 5).
67 is in this sequence because sqrt(67) = 8.185352..., and -67 is quadratic nonresidue mod all odd primes < 8.185352... not dividing 67 (mod 3, mod 5 and mod 7).
17 is not in this sequence because -17 is quadratic residue mod 3 and 3 < sqrt(17) and 3 does not divide 17.
90 is not in this sequence because -90 is quadratic residue mod 7 and 7 < sqrt(90) and 7 does not divide 90.
For n < 9, the range of p is empty, thus the numbers n < 9 are trivially in this sequence.
PROG
(PARI) a(n)=forprime(p=3, , if(kronecker(-n, p)==1, return(p)))
for(k=1, 10^6, if(a(k)>sqrt(k), print1(k, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Richard N. Smith, Jul 13 2019
STATUS
approved