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

A386865

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

Terms

    a(0) =1a(1) =6a(2) =51a(3) =496a(4) =5130a(5) =54894a(6) =600103a(7) =6657312a(8) =74646702a(9) =843819580a(10) =9599776494a(11) =109776491664

External references