OFFSET
1,1
COMMENTS
Except for primes 2, 5, 13 and 37, this sequence consists all primes p such that p = 7 (mod 8). The density of these primes is 0.25.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
MATHEMATICA
lst={}; lim=32; Do[n=a^2+b^2+c^2; If[n<lim^2 && PrimeQ[n], lst=Union[lst, {n}]], {a, lim}, {b, a, Sqrt[lim^2-a^2]}, {c, b, Sqrt[lim^2-a^2-b^2]}]; Complement[Prime[Range[PrimePi[lst[[ -1]]]]], lst]
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, May 21 2004
STATUS
approved