a(n) = Sum_{k=0..n} (n!/(n - k)!)^k.A295610a(n) = Sum_{k=0..n} (n!/(n - k)!)^k.Terms a(0) =1a(1) =2a(2) =7a(3) =256a(4) =345749a(5) =25090776406External referencesoeis: A295610