a(n) = U(3*n, n), where U(n, x) is the Chebyshev polynomial of the second kind.

A349074

a(n) = U(3*n, n), where U(n, x) is the Chebyshev polynomial of the second kind.

Terms

    a(0) =1a(1) =4a(2) =2911a(3) =7997214a(4) =57641556673

External references