%I #3 Mar 30 2012 17:33:56
%S 6,28,496,8128,33550336,8589869056,137438691328,2305843008139952128,
%T 2658455991569831744654692615953842176,
%U 14474011154664524427946373126085988481573677491474835889066354349131199152128
%N a(n) = A136007(n)*(A136007(n)+1)/2.
%C Different from A000396.
%Y Cf. A000396, A136007.
%K nonn
%O 1,1
%A _Omar E. Pol_, Dec 15 2008