OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) == 1 (mod 4). - Thomas Ordowski, Mar 13 2018
EXAMPLE
The prime 13 = 2^2 + 3^2 is a term, since 13 - 2*3 = 7 is prime and 13 + 2*3 = 19 is prime.
MATHEMATICA
prsQ[{a_, b_}]:=Module[{c=a^2+b^2, d=a*b}, And@@PrimeQ[c+{0, d, -d}]]; Sort[#[[1]]^2+#[[2]]^2&/@Select[Subsets[Range[100], {2}], prsQ]] (* Harvey P. Dale, Apr 27 2014 *)
PROG
(PARI) list(lim)=my(v=List(), t); for(a=1, sqrt(lim), forstep(b=1+a%2, min(a, sqrt(lim-a^2)), 2, if(isprime(t=a^2+b^2) && isprime(t-a*b) && isprime(t+a*b), listput(v, t)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Apr 25 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Thomas Ordowski, Apr 24 2012
EXTENSIONS
a(6)-a(46) from Charles R Greathouse IV, Apr 25 2012
STATUS
approved