a(n) = (n - 1)! * d(n), where d(n) = number of divisors of n (A000005).

A318249

a(n) = (n - 1)! * d(n), where d(n) = number of divisors of n (A000005).

Terms

    a(0) =1a(1) =2a(2) =4a(3) =18a(4) =48a(5) =480a(6) =1440a(7) =20160a(8) =120960a(9) =1451520a(10) =7257600a(11) =239500800a(12) =958003200a(13) =24908083200a(14) =348713164800

External references