A036950 - OEIS

%I #14 Mar 09 2020 12:27:34

%S 7,79,797,0,77797,777977,7777997,77779799,777777799,7777779799,

%T 77777779979,777777779777,7777777779977,77777777777977,

%U 777777777779797,7777777777797799,77777777777777797,777777777777797977

%N Smallest n-digit prime containing only the digits 7 and 9, or 0 if no such prime exists.

%H Jinyuan Wang, <a href="/A036950/b036950.txt">Table of n, a(n) for n = 1..500</a>

%Y Cf. A020471, A036229, A036324.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, Jan 04 1999