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%I #11 Nov 28 2016 03:59:23
%S 11,113,11777,1133333,1199999,113333333,11777777777,
%T 1111111111111111111,11111111111111111111111,
%U 1177777777777777777777777,113333333333333333333333333,1177777777777777777777777777777777777777777777777
%N Primes of the form identical digits preceded by an 11.
%H Vincenzo Librandi, <a href="/A201966/b201966.txt">Table of n, a(n) for n = 1..16</a>
%t Select[FromDigits/@Flatten[Table[PadRight[{11},i,#]&/@{1,2,3,4,5,6,7,8,9},{i,2,1200}],1],PrimeQ[#]&]
%K nonn,base,less
%O 1,1
%A _Vincenzo Librandi_, Dec 10 2011