Coefficient of x^n in (1 + n*x + x^3)^n.
A307905
Coefficient of x^n in (1 + n*x + x^3)^n.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =30a(4) =304a(5) =3875a(6) =59631a(7) =1076383a(8) =22309120a(9) =522262245a(10) =13631508400a(11) =392535959156
External references
- oeis: A307905