OFFSET
1,1
COMMENTS
Suggestion: difference between successive terms is always at least 3. (With the known 115885 terms <10^9, the smallest difference is 24.) - Zak Seidov, Jun 12 2013
REFERENCES
Stan Wagon, Mathematica in Action, Springer, 2000 (2nd ed.), Ch. 17.5, pp. 375-378.
LINKS
Zak Seidov, Table of n, a(n) for n = 1..2464 (all terms up to 10^7).
EXAMPLE
2210 = 19^2 + 43^2 = 23^2 + 41^2 = 29^2 + 37^2;
MAPLE
Prime2PairsSum := s -> select( x -> `if`(andmap(isprime, x), true, false), numtheory:-sum2sqr(s)):
for n from 2 to 10 do
if nops(Prime2PairsSum(n)) = 3 then print(n, Prime2PairsSum(n)) fi
od;
MATHEMATICA
Select[Range@20000, Length[Select[ PowersRepresentations[#, 2, 2], And @@ PrimeQ[#] &]] == 3 &] (* Giovanni Resta, Jun 11 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Henk Koppelaar, Jun 11 2013
EXTENSIONS
a(22)-a(37) from Giovanni Resta, Jun 11 2013
STATUS
approved