a(n) = Sum_{i=1..n} Product_{j=(i-1)*n+1..i*n} j.

A336513

a(n) = Sum_{i=1..n} Product_{j=(i-1)*n+1..i*n} j.

Terms

    a(0) =1a(1) =14a(2) =630a(3) =57264a(4) =8626800a(5) =1940869440a(6) =609372212400

External references