%I #3 Mar 30 2012 17:30:36
%S 2,11,20,83,149,188,209,326,347,566,944,1301,1565,1574,1607,1805,1892,
%T 1943,2102,2228,2531,3173,3485,4379,5135,5534,6299,6722,6950,7223,
%U 7727,7970,8105,8273,8882,9785,9914,10112,10985,11654,11930,12221,13547
%N Numbers n such that n*10-1, n*10-3, n*10-7 and n*10-9 are all prime.
%t Select[Range[10^5], PrimeQ[10# - 1] && PrimeQ[10# - 3] && PrimeQ[10# - 7] && PrimeQ[10# - 9] &]
%K easy,nonn
%O 1,1
%A _Robert G. Wilson v_, Oct 30 2001