a(n) = cos(2*n*arccos(sqrt(n))).

A173148

a(n) = cos(2*n*arccos(sqrt(n))).

Terms

    a(0) =1a(1) =1a(2) =17a(3) =485a(4) =18817a(5) =930249a(6) =55989361a(7) =3974443213a(8) =325142092801

External references