a(n) = n! a(n-1) / a(n-2), where a(0) = 1, a(1) = 2.
A372994
a(n) = n! a(n-1) / a(n-2), where a(0) = 1, a(1) = 2.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =12a(4) =72a(5) =720a(6) =7200a(7) =50400a(8) =282240a(9) =2032128a(10) =26127360a(11) =513216000a(12) =9408960000a(13) =114162048000
External references
- oeis: A372994