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Least n-digit prime using digit 7 once and rest all 1, or 0 if no such prime exists.
3

%I #4 Dec 05 2013 19:56:38

%S 7,17,0,1117,11117,0,1111711,11111117,0,1117111111,17111111111,0,

%T 1111171111111,0,0,0,11111111111111171,0,1111111111111111171,

%U 11111111111111117111,0,1111111111111111111711,11111111111111111111117

%N Least n-digit prime using digit 7 once and rest all 1, or 0 if no such prime exists.

%C a(3n) = 0.

%e a(5) = 11117.

%Y Cf. A090536, A090537, A090538.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Dec 08 2003

%E More terms from _David Wasserman_, Jan 03 2006