%I #9 Mar 09 2020 10:26:39
%S 0,11,181,1181,18181,0,1111181,11818181,111111181,1111111181,
%T 11111188811,0,1111111118111,11111111818181,111111111111881,
%U 1111111111111181,11111111111188111,0,1111111111111111111
%N Smallest n-digit prime containing only digits 1 and 8, or 0 if no such prime exists.
%C a(6k) = 0 as any 6k-digit number containing only digits 1 or 8 is divisible by 7. - _Jinyuan Wang_, Mar 09 2020
%H Jinyuan Wang, <a href="/A036935/b036935.txt">Table of n, a(n) for n = 1..500</a>
%Y Cf. A020456, A036229, A036308.
%K nonn,base
%O 1,2
%A _Patrick De Geest_, Jan 04 1999