a(n) = n! * Sum_{k=0..floor(n/3)} (n - 3*k)^n/(n - 3*k)!.
A357174
a(n) = n! * Sum_{k=0..floor(n/3)} (n - 3*k)^n/(n - 3*k)!.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =27a(4) =280a(5) =5045a(6) =134136a(7) =4269223a(8) =153188176a(9) =6657007113a(10) =371930499280
External references
- oeis: A357174