%I #3 Jan 21 2019 19:01:55
%S 2,4,32,32768,4503599627370496,
%T 12855504354071922204335696738729300820177623950262342682411008
%N a(n) = 2^(Bell_Number(n)).
%p seq(2^bell(x),x=1..6);
%Y Cf. A000110.
%K nonn
%O 1,1
%A _Jorge Coveiro_, Dec 26 2004
