%I

%S 2,4,8,22,98,388,16648,132358,1311234,1073743876,17179877384,

%T 274877943814,4398113693698,72083983122432004,3458834890081107976,

%U 110681871838615896070,38686511673635471463677954,2475908412805686633409019908,198070557401964757114570145800

%N {2^n}_{2^n}.

%C See A122618 for notation.

%K nonn,base

%O 1,1

%A _N. J. A. Sloane_, Sep 21 2006