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

A352277

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

Terms

    a(0) =1a(1) =-2a(2) =10a(3) =-62a(4) =250a(5) =3538a(6) =-109430a(7) =376738a(8) =64406170a(9) =-1496149262a(10) =-66387156950

External references