OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3)=23 because (19^2 + 23^2 + 29^2)/3 = 1731/3 = 577 is prime.
MAPLE
q:= 5: r:= 7:
Res:= NULL: count:= 0:
while count < 100 do
p:= q;
q:= r;
r:= nextprime(r);
if isprime((p^2+q^2+r^2)/3) then count:= count+1; Res:= Res, q fi
od:
Res; # Robert Israel, Aug 20 2018
MATHEMATICA
Select[Partition[Prime[Range[400]], 3, 1], PrimeQ[Total[#^2]/3]&][[;; , 2]] (* Harvey P. Dale, Sep 08 2023 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Hugo Pfoertner, Jun 14 2003
STATUS
approved