a(n) = n! * Sum_{k=1..n} Sum_{d|k} 1/(d * (k/d)^d).

A356406

a(n) = n! * Sum_{k=1..n} Sum_{d|k} 1/(d * (k/d)^d).

Terms

    a(0) =1a(1) =4a(2) =16a(3) =79a(4) =443a(5) =2968a(6) =22216a(7) =189698a(8) =1792402a(9) =18745036a(10) =213452996a(11) =2653142952a(12) =35448861576a(13) =509724975264

External references