OFFSET
1,1
COMMENTS
Primes p such that 8*p+9, 64*p+81, 512*p+657, 4096*p+5265 and 32768*p+42129 are also primes. - Vincenzo Librandi, Aug 05 2010
LINKS
John Cerkan, Table of n, a(n) for n = 1..10000
FORMULA
a(n) == 23 (mod 70). - John Cerkan, Nov 13 2016
MATHEMATICA
prp5Q[n_]:=AllTrue[Rest[NestList[8#+9&, n, 5]], PrimeQ]; Select[Prime[Range[3513000]], prp5Q] (* Harvey P. Dale, May 25 2024 *)
prp5Q2[n_] := AllTrue[NestList[8 # + 9 &, n, 5], PrimeQ]; Select[Range[23, 59120000, 70], prp5Q2] (* Faster than the first Mathematica program above. *) (* Harvey P. Dale, May 25 2024 *)
PROG
(Magma) [n: n in [1..19000000] | IsPrime(n) and IsPrime(8*n+9) and IsPrime(64*n+81) and IsPrime(512*n+657) and IsPrime(4096*n+5265) and IsPrime(32768*n+42129)] // Vincenzo Librandi, Aug 05 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved