a(n) = U(n, 2*n), where U(n, x) is the Chebyshev polynomial of the second kind.

A349075

a(n) = U(n, 2*n), where U(n, x) is the Chebyshev polynomial of the second kind.

Terms

    a(0) =1a(1) =4a(2) =63a(3) =1704a(4) =64769a(5) =3168060a(6) =189447551a(7) =13389885712

External references