G.f.: Sum_{n>=0} 3^n * ((1+x)^n - 1)^n.

A301582

G.f.: Sum_{n>=0} 3^n * ((1+x)^n - 1)^n.

Terms

    a(0) =1a(1) =3a(2) =36a(3) =765a(4) =22932a(5) =886707a(6) =41971041a(7) =2349915543a(8) =151893243711

External references