G.f.: Sum_{n>=0} (n+1) * x^n * ((1+x)^n + 1)^n / (1 + x*(1+x)^n)^(n+2).

A326006

G.f.: Sum_{n>=0} (n+1) * x^n * ((1+x)^n + 1)^n / (1 + x*(1+x)^n)^(n+2).

Terms

    a(0) =1a(1) =2a(2) =5a(3) =10a(4) =35a(5) =110a(6) =484a(7) =2090a(8) =10449a(9) =54526a(10) =306394a(11) =1817190a(12) =11357273a(13) =74488856a(14) =510662890a(15) =3649746072a(16) =27120964497a(17) =209070202378

External references