%I M2707 #12 Apr 27 2016 07:55:30
%S 3,7,127,170141183460469231731687303715884105727
%N a(n+1) = 2^a(n) - 1.
%D P. Ribenboim, The Book of Prime Number Records. Springer-Verlag, NY, 2nd ed., 1989, p. 81.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%Y Subsequence of A007013.
%K dead
%O 0,1