G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (n + k*x) / (1 + n*x + k*x^2).
A204066
G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (n + k*x) / (1 + n*x + k*x^2).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =16a(4) =82a(5) =502a(6) =3574a(7) =29002a(8) =264166a(9) =2668666a(10) =29612014a(11) =358025986a(12) =4684916902a(13) =65966957722a(14) =994546450174
External references
- oeis: A204066