%I #9 Feb 18 2019 06:05:17
%S 3,7,31,127,8191,131071,524287,2147483647,8796093022207,
%T 2305843009213693951,604462909807314587353087,
%U 618970019642690137449562111,162259276829213363391578010288127,170141183460469231731687303715884105727
%N Numbers of the form 2^p - 1, with p prime, for which each prime divisor has the form 4j + 3.
%C The Mersenne primes (A000668) are contained in this sequence.
%C Needed factorizations are in the Cunningham Project.
%H Amiram Eldar, <a href="/A183077/b183077.txt">Table of n, a(n) for n = 1..26</a>
%H S. S. Wagstaff, Jr., <a href="http://homes.cerias.purdue.edu/~ssw/cun/index.html">The Cunningham Project</a>.
%F a(n) = 2^A183073(n) - 1.
%e 8796093022207 = 2^43 - 1 = 431 * 9719 * 2099863.
%Y Cf. A000668, A136005, A183075, A183076, A183078.
%Y Cf. A000043, A136003, A183071, A183072, A183073, A183074.
%K nonn,hard
%O 1,1
%A _Stuart Clary_, Dec 23 2010