The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #2 Mar 30 2012 18:59:02
%S 1,2,6,12,60,180,900,1800,3600,18000,54000,162000,486000,2430000,
%T 4860000,9720000,29160000,58320000,116640000,583200000,1749600000,
%U 5248800000,10497600000,31492800000,62985600000,188956800000
%N a(n)=Product{k=0..n, 1+2^A101650(k)}/2.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Dec 10 2004