Non-trivial Intertwined Second-order Recurrence Relations

@inproceedings{Hirschhorn2003NontrivialIS,
  title={Non-trivial Intertwined Second-order Recurrence Relations},
  author={Michael D. Hirschhorn},
  year={2003}
}
In a recently published book, it is shown that there are essentially seven different non– trivial systems of three intertwined second–order recurrence relations, but the solutions are not given. In this note we present explicit solutions to all seven systems. AMS Classification: 11B39, 11B37