a(n) = Product_{k=0..n} binomial(4*k,k).A262261a(n) = Product_{k=0..n} binomial(4*k,k).Terms a(0) =1a(1) =4a(2) =112a(3) =24640a(4) =44844800a(5) =695273779200External referencesoeis: A262261