a(n) = Product_{k=1..n} (81 - 9/k).A216705a(n) = Product_{k=1..n} (81 - 9/k).Terms a(0) =1a(1) =72a(2) =5508a(3) =429624a(4) =33832890a(5) =2679564888a(6) =213025408596External referencesoeis: A216705