  In this paper, we give several matrix representations for the Horadam
quaternions. We derive several identities related to these quaternions by using
the matrix method. Since quaternion multiplication is not commutative, some of
our results are non-commutative analogues of the well known identities for the
Fibonacci-like integer sequences. Lastly, we derive some binomial-sum
identities for the Horadam quaternions as an application of the matrix method.
