O.g.f.: Sum_{n>=0} 3*(n+3)^(n-1) * x^n / Product_{k=1..n} (1+k*x).
A196556
O.g.f.: Sum_{n>=0} 3*(n+3)^(n-1) * x^n / Product_{k=1..n} (1+k*x).
Terms
- a(0) =1a(1) =3a(2) =12a(3) =66a(4) =483a(5) =4476a(6) =50454a(7) =671649a(8) =10328118a(9) =180341094a(10) =3527385345a(11) =76435691250
External references
- oeis: A196556