a(n) = -cos((2*n-1)*arcsin(sqrt(3)))^2 = -1 + cosh((2*n-1)*arcsinh(sqrt(2)))^2.

A146312

a(n) = -cos((2*n-1)*arcsin(sqrt(3)))^2 = -1 + cosh((2*n-1)*arcsinh(sqrt(2)))^2.

Terms

    a(0) =2a(1) =242a(2) =23762a(3) =2328482a(4) =228167522a(5) =22358088722

External references