a(n) = n!^2 * Sum_{k=1..n} mu(k)/k^2, where mu(k) is the Moebius function.
A068338
a(n) = n!^2 * Sum_{k=1..n} mu(k)/k^2, where mu(k) is the Moebius function.
Terms
- a(0) =1a(1) =3a(2) =23a(3) =368a(4) =8624a(5) =324864a(6) =15399936a(7) =985595904a(8) =79833268224
External references
- oeis: A068338