a(n) = (n!)^2 * Sum_{k=0..n-1} 1 / ((n-k)^2 * k!).
A346405
a(n) = (n!)^2 * Sum_{k=0..n-1} 1 / ((n-k)^2 * k!).
Terms
- a(0) =0a(1) =1a(2) =5a(3) =31a(4) =268a(5) =3476a(6) =70656a(7) =2202432a(8) =98622336a(9) =5954736384a(10) =463100042880
External references
- oeis: A346405