OFFSET
1,1
COMMENTS
Primes p such that 3*p+10, 9*p+40, 27*p+130 and 81*p+400 are also primes. - Vincenzo Librandi, Aug 04 2010
LINKS
John Cerkan, Table of n, a(n) for n = 1..10000
FORMULA
a(n) == 3 or 9 (mod 14). - John Cerkan, Oct 04 2016
MATHEMATICA
Select[Range[10^5], Times @@ Boole@ PrimeQ@ NestList[3 # + 10 &, #, 4] > 0 &] (* Michael De Vlieger, Oct 04 2016 *)
PROG
(Magma) [n: n in [1..1000000] | IsPrime(n) and IsPrime(3*n+10) and IsPrime(9*n+40) and IsPrime(27*n+130) and IsPrime(81*n+400)] // Vincenzo Librandi, Aug 04 2010
(PARI) is(n)=isprime(n) && isprime(3*n+10) && isprime(9*n+40) && isprime(27*n+130) && isprime(81*n+400) \\ Charles R Greathouse IV, Oct 04 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved