A243408 Primes p such that 10p-1, 10p-3, 10p-7 and 10p-9 are all prime.

2, 11, 83, 149, 347, 1301, 1607, 2531, 6299, 7727, 8273, 17117, 20183, 21737, 24371, 26669, 39227, 40277, 53951, 54917, 63347, 66359, 66467, 73637, 82217, 82373, 101537, 102251, 106397, 106871, 117203, 132971, 134033, 135221, 140237, 144701, 146141, 151433, 152597

Offset

1,1

Comments

This is a subsequence of A064975.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

2 is prime, 10*2-1 = 19 is prime, 10*2-3 = 17 is prime, 10*2-7 = 13 is prime, 10*2-9 = 11 is prime. Thus 2 is a member of this sequence.

Mathematica

Select[ Range@ 153000], PrimeQ[#] && PrimeQ[10#-1] && PrimeQ[10#-3] && PrimeQ[10#-7] && PrimeQ[10#-9] &] (* Robert G. Wilson v, Jun 06 2014 *)
Select[Prime[Range[15000]], AllTrue[10#-{1, 3, 7, 9}, PrimeQ]&] (* Harvey P. Dale, Aug 18 2024 *)

Prog

(Python)
import sympy
from sympy import isprime
from sympy import prime
{print(prime(n), end=', ') for n in range(1, 10**5) if isprime(10*prime(n)-1) and isprime(10*prime(n)-3) and isprime(10*prime(n)-7) and isprime(10*prime(n)-9)}
(PARI) for(n=1, 10^5, if(ispseudoprime(10*prime(n)-1) && ispseudoprime(10*prime(n)-3) && ispseudoprime(10*prime(n)-7) && ispseudoprime(10*prime(n)-9), print1(prime(n), ", ")))

Crossrefs

Cf. A067267, A064975.

Sequence in context: A378954 A293574 A322644 * A352655 A104086 A143140

Adjacent sequences: A243405 A243406 A243407 * A243409 A243410 A243411

Keyword

nonn

Author

Derek Orr, Jun 04 2014

Status

approved