OFFSET
1,2
MAPLE
isA263309 := proc(n)
if isprime(6*n+1) then
if isprime(36*n+7) then
true;
else
false;
end if;
else
false;
end if;
end proc:
for n from 1 to 100 do
if isA263309(n) then
printf("%d, ", n);
end if;
end do: # R. J. Mathar, Oct 17 2015
MATHEMATICA
Select[Range[1000], PrimeQ[p=6*#+1]&& PrimeQ[q=6*p+1]&]
PROG
(PARI) isok(n) = isprime(p=6*n+1) && isprime(6*p+1); \\ Michel Marcus, Oct 17 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 13 2015
STATUS
approved