OFFSET
1,1
COMMENTS
LINKS
John Cerkan, Table of n, a(n) for n = 1..10000
FORMULA
{p, 6p+1, 36p+7, 216p+43} are all primes, where p is prime.
EXAMPLE
First chain is {61, 367, 2203, 13219};
319th chain is {1291391, 7748347, 46490083, 278940499}.
MATHEMATICA
k=0; m=6; Do[s=Prime[n]; s1=m*s+1; s2=m*s1+1; s3=m*s2+1; If[PrimeQ[s1]&&PrimeQ[s2]&&PrimeQ[s3], k=k+1; Print[{k, n, s, s1, s2, s3}]], {n, 1, 100000}] (* edited by Zak Seidov, Feb 08 2011 *)
thrQ[n_]:=AllTrue[Rest[NestList[6#+1&, n , 3]], PrimeQ]; Select[Prime[Range[9000]], thrQ] (* Harvey P. Dale, Mar 03 2024 *)
PROG
(Magma) [n: n in [1..150000] | IsPrime(n) and IsPrime(6*n+1) and IsPrime(36*n+7) and IsPrime(216*n+43)] // Vincenzo Librandi, Aug 04 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Additional comments from Labos Elemer, Jul 23 2003
STATUS
approved