a(n) = ( Sum_{k=0..n} binomial(2*n, k)^2 * (binomial(2*n, k+1) - binomial(2*n, k-1)) )/(n*binomial(2*n, n)).

A259335

a(n) = ( Sum_{k=0..n} binomial(2*n, k)^2 * (binomial(2*n, k+1) - binomial(2*n, k-1)) )/(n*binomial(2*n, n)).

Terms

    a(0) =1a(1) =7a(2) =61a(3) =611a(4) =6686a(5) =77729a(6) =944245a(7) =11859355a(8) =152893720a(9) =2013070126a(10) =26967817306a(11) =366542344117

External references