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

A349076

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

Terms

    a(0) =1a(1) =6a(2) =143a(3) =5796a(4) =330049a(5) =24192090a(6) =2168392031a(7) =229755926568

External references