a(n) = Sum_{k=0..n} (k*n)^n.A349964a(n) = Sum_{k=0..n} (k*n)^n.Terms a(0) =1a(1) =1a(2) =20a(3) =972a(4) =90624a(5) =13828125a(6) =3133930176a(7) =988501957072External referencesoeis: A349964