Coefficient of x^n in (1 + (n+1)*x + n*x^2)^n.
A187021
Coefficient of x^n in (1 + (n+1)*x + n*x^2)^n.
Terms
- a(0) =1a(1) =2a(2) =13a(3) =136a(4) =1921a(5) =33876a(6) =712909a(7) =17383584a(8) =481003009a(9) =14869654300a(10) =507406003501
External references
- oeis: A187021