OFFSET
1,1
COMMENTS
LINKS
Zak Seidov, Table of n, a(n) for n = 1..20000
Wikipedia, Cunningham chain
MAPLE
isA263311 := proc(n)
return isprime(6*n+1) and isprime(36*n+7) and isprime(216*n+43) and isprime(1296*n+259) ;
end proc:
for n from 1 to 30000 do
if isA263311(n) then
printf("%d, ", n);
end if;
end do; # R. J. Mathar, Oct 17 2015
MATHEMATICA
Select[Range[10, 100000, 5], PrimeQ[p=6*#+1]&&PrimeQ[q=6*p+1]&&PrimeQ[r=6*q+1]&&PrimeQ[s=6*r+1]&]
PROG
(PARI) for(n=1, 1e5, if(isprime(p=6*n+1) && isprime(q=6*p+1) && isprime(r=6*q+1) && isprime(6*r+1), print1(n", "))) \\ Altug Alkan, Oct 17 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 13 2015
STATUS
approved