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n*10^4-1, n*10^4-3, n*10^4-7 and n*10^4-9 are all prime.
0

%I #2 Mar 30 2012 17:30:36

%S 1856,13301,14003,15545,21155,21593,24851,27557,37952,40013,44906,

%T 48515,53294,53891,59162,62282,62798,65714,71900,72560,74093,77915,

%U 79910,80426,83252,91421,99632,112829,118364,121367,136025,138848

%N n*10^4-1, n*10^4-3, n*10^4-7 and n*10^4-9 are all prime.

%t Select[ Range[200000], PrimeQ[10^4# - 1] && PrimeQ[10^4# - 3] && PrimeQ[10^4# - 7] && PrimeQ[10^4# - 9] &]

%K easy,nonn

%O 1,1

%A _Robert G. Wilson v_, Oct 30 2001