The K-type formulas of the space of K-finite solutions to the Heisenberg ultrahyperbolic equation sf = 0 for the non-linear group SL(3, R) are classified. This completes a previous study of Kable for the linear group SL(m, R) in the case of m = 3, as well as generalizes our earlier results on a certain second order differential operator. As a by-product we also show several properties of certain sequences {Pj (x; y)} ∞ j=0 and {Qj(x; y)} ∞ j=0 of tridiagonal determinants, whose generating functions are given by local Heun functions. In particular, it is shown that these sequences satisfy a certain arithmetic-combinatorial property, which we refer to as a palindromic property. We further show that classical sequences of Cayley continuants {Cay j (x; y)} ∞ j=0 and Krawtchouk polynomials {Kj (x; y)} ∞ j=0 also admit this property. In the end a new proof of Sylvester's formula for certain tridiagonal determinant Sylv(x; n) is provided from a representation theory point of view.