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n*10^3-1, n*10^3-3, n*10^3-7 and n*10^3-9 are all prime.
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%I #6 Aug 01 2017 17:11:50

%S 248,302,1094,5462,6716,7274,7478,9542,10193,13217,16199,18560,20714,

%T 22205,28856,29843,31949,34457,35387,36767,36977,36983,40958,41393,

%U 45167,45347,47273,47468,47567,57101,57515,57773,62156,64331,66704

%N n*10^3-1, n*10^3-3, n*10^3-7 and n*10^3-9 are all prime.

%H Harvey P. Dale, <a href="/A064977/b064977.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[40000], PrimeQ[10^3# - 1] && PrimeQ[10^3# - 3] && PrimeQ[10^3# - 7] && PrimeQ[10^3# - 9] &]

%t Select[Range[70000],AllTrue[# 10^3-{1,3,7,9},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Aug 01 2017 *)

%K easy,nonn

%O 1,1

%A _Robert G. Wilson v_, Oct 30 2001