a(n) = Sum_{k=0..floor(n/3)} (-1)^k * (n-3*k)!.
A358608
a(n) = Sum_{k=0..floor(n/3)} (-1)^k * (n-3*k)!.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =23a(5) =118a(6) =715a(7) =5017a(8) =40202a(9) =362165a(10) =3623783a(11) =39876598a(12) =478639435a(13) =6223397017a(14) =87138414602
External references
- oeis: A358608