OFFSET
1,1
COMMENTS
Primes p such that 5*p+4, 25*p+24, 125*p+124, 625*p+624 and 3125*p+3124 are also primes. - Vincenzo Librandi, Aug 05 2010
LINKS
John Cerkan, Table of n, a(n) for n = 1..10000
FORMULA
a(n) == 41 (mod 42). - John Cerkan, Oct 20 2016
MATHEMATICA
Select[Prime[Range[500000]], AllTrue[Rest[NestList[5#+4&, #, 5]], PrimeQ]&] (* Harvey P. Dale, Jan 01 2022 *)
PROG
(Magma) [n: n in [1..10000000] | IsPrime(n) and IsPrime(5*n+4) and IsPrime(25*n+24) and IsPrime(125*n+124) and IsPrime(625*n+624) and IsPrime(3125*n+3124)] // Vincenzo Librandi, Aug 05 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved