G.f.: exp(Sum_{k>=1} (5*k)!/k!^5 * x^k/k).A333043G.f.: exp(Sum_{k>=1} (5*k)!/k!^5 * x^k/k).Terms a(0) =1a(1) =120a(2) =63900a(3) =63148000a(4) =85136103750External referencesoeis: A333043