O.g.f.: Sum_{n>=0} 2*n^n * (n+2)^(n-1) * exp(-n*(n+2)*x) * x^n / n!.

A217901

O.g.f.: Sum_{n>=0} 2*n^n * (n+2)^(n-1) * exp(-n*(n+2)*x) * x^n / n!.

Terms

    a(0) =1a(1) =2a(2) =10a(3) =106a(4) =1736a(5) =38414a(6) =1073178a(7) =36281032a(8) =1441336688a(9) =65849949118

External references