OFFSET
1,1
EXAMPLE
p^2 + q^2 = 2r with r equal [(p+q)/2]^2 + [q -(p+q)/2]^2.
MATHEMATICA
Select[Union[Total[#^2]&/@Tuples[Prime[Range[20]], 2]], EvenQ[#] && PrimeOmega[#] == 2&] (* Harvey P. Dale, Jun 18 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Mar 27 2005; corrected Mar 29 2005
STATUS
approved