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Numbers k such that 1000k+1, 1000k+3, 1000k+7, 1000k+9 are all primes.
2

%I #13 Jun 19 2018 03:27:54

%S 13,1447,2062,5527,6760,8062,11554,11890,14467,23113,23482,24952,

%T 25150,28201,28300,31072,31576,36217,41584,41599,45331,50635,56914,

%U 66688,67639,69376,75079,80002,81157,82240,84517,88948,90010,90376,91018

%N Numbers k such that 1000k+1, 1000k+3, 1000k+7, 1000k+9 are all primes.

%H Harry J. Smith, <a href="/A064962/b064962.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[10^5], PrimeQ[1000# + 1] && PrimeQ[1000# + 3] && PrimeQ[1000# + 7] && PrimeQ[1000# + 9] &]

%o (PARI) { n=0; for (m=1, 10^9, if(isprime(1000*m + 1) && isprime(1000*m + 3) && isprime(1000*m + 7) && isprime(1000*m + 9), write("b064962.txt", n++, " ", m); if (n==1000, return)) ) } \\ _Harry J. Smith_, Oct 01 2009

%Y Cf. A007811, A064687.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Oct 29 2001