a(n) = n!*LaguerreL(n, -6*n).A277420a(n) = n!*LaguerreL(n, -6*n).Terms a(0) =1a(1) =7a(2) =194a(3) =9078a(4) =596760a(5) =50508120a(6) =5228520912a(7) =639915545808External referencesoeis: A277420