OFFSET
1,1
COMMENTS
These primes split in O_(Q(sqrt(-43))) (note that 43 ramifies, since it's divisible by -43). For the primes p listed here that are less than 43, note that 4p = 43 + x^2. For example, 4 * 13 = 52 = 43 + 3^2, 4 * 17 = 68 = 43 + 5^2. - Alonso del Arte, Apr 03 2018
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Prime[Range[200]], JacobiSymbol[#, 43] == 1 &]
PROG
(Magma) [p: p in PrimesUpTo(569) | JacobiSymbol(p, 43) eq 1]; // Vincenzo Librandi, Sep 10 2012
(PARI) isok(n) = isprime(n) && issquare(Mod(n, 43)); \\ Michel Marcus, Apr 15 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, May 24 2011
STATUS
approved