a(n) = floor(n^n / n!).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =26a(6) =64a(7) =163a(8) =416a(9) =1067a(10) =2755a(11) =7147a(12) =18613a(13) =48638a(14) =127463a(15) =334864a(16) =881657a(17) =2325750a(18) =6145596a(19) =16263866a(20) =43099804a(21) =114356611a(22) =303761260a(23) =807692034a(24) =2149632061a(25) =5726042115a(26) =15264691107a(27) =40722913454a(28) =108713644516