OFFSET
1,1
COMMENTS
Real primes 2,5,13,17,29,37,... have a unique representation as sum of two squares. Values larger 2 are the primes p with p = 1 mod 4. This is sequence A002313. If p = x^2 + y^2, the corresponding complex prime is x+y*i First complex prime is 1+i with 2 as corresponding real prime, according to reference, page 1-2.
REFERENCES
Handbook of First Complex Prime Numbers, Part1 + 2 Ervand Kogbetliantz and Alice Krikorian, Gordon and Breach, 1971
EXAMPLE
89 is the 11th prime in sequence A002313, 11*8 = 88, so 89 = 1 mod 11
MATHEMATICA
Module[{nn=112*10^6, pr, len}, pr=Select[Prime[Range[nn]], MemberQ[ {1, 2}, Mod[ #, 4]]&]; len=Length[pr]; Select[Thread[{pr, Range[len]}], Mod[ #[[1]], #[[2]]] == 1&]][[All, 1]] (* Harvey P. Dale, Aug 13 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Sven Simon, May 17 2003
STATUS
approved