a(n) = n! * Sum_{k=0..floor(n/5)} (n/5)^k / (k! * (n-5*k)!).
A362319
a(n) = n! * Sum_{k=0..floor(n/5)} (n/5)^k / (k! * (n-5*k)!).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =121a(6) =865a(7) =3529a(8) =10753a(9) =27217a(10) =7318081a(11) =96720625a(12) =689990401a(13) =3508289929a(14) =14239793569
External references
- oeis: A362319