%I #2 Mar 31 2012 10:22:16
%S 1,8,193,16448,5253121,6447694208,30795721162753,576522325894105088,
%T 42502811563960266915841,12379542064132015743721023488,
%U 14278867426031486089248841370959873
%N a(n)=((2^n+1)^n-(2^n-1)^n)/2
%t Table[((2^x + 1)^x - (2^x - 1)^x)/2, {x, 1, 15}]
%K nonn
%O 1,2
%A _Artur Jasinski_, Feb 01 2010