%I A082719
%S A082719 7,73,97,115,205,985,1227,4795,20721
%N A082719 Plateau and depression primes of the form 8*(10^a(n)-1)/9+(10^[ a(n)-1 
               ]+1) or (89*10^[ a(n)-1 ]+1)/9.
%C A082719 Prime versus probable prime status and proofs are given in the author's 
               table.
%D A082719 C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 
               28, No. 1, 1996-97, pp. 1-9.
%H A082719 P. De Geest, <a href="http://www.worldofnumbers.com/deplat.htm">PDP Reference 
               Table</a>
%e A082719 a(n)=7 -> 8*(10^7-1)/9+(10^6+1) = 9888889.
%Y A082719 Cf. A082697 up to A082719.
%Y A082719 Sequence in context: A137730 A157920 A080794 this_sequence A142053 A012049 
               A012158
%Y A082719 Adjacent sequences: A082716 A082717 A082718 this_sequence A082720 A082721 
               A082722
%K A082719 nonn,base
%O A082719 0,1
%A A082719 Patrick De Geest (pdg(AT)worldofnumbers.com), Apr 13 2003.