a(n) = ( Product_{k=2..n-1} k^k )^2*2^n.A369699a(n) = ( Product_{k=2..n-1} k^k )^2*2^n.Terms a(0) =1a(1) =2a(2) =4a(3) =128a(4) =186624a(5) =24461180928External referencesoeis: A369699