**MSC:**- 05C70 Factorization, matching, covering and packing
- 05C45 Eulerian and Hamiltonian graphs

set of isomorphic graphs such that two

of them share exactly one edge and all together cover the complete graph

twice. In the case of

paths the problem is also known as self-orthogonal Hamilton path

decomposition of $2K_n$. Solutions generated by a group correspond to

self-orthogonal $2$-sequencings of this group.

We present small solutions which can be applied to

a well-known recursive construction. This gives new classes of such ODCs.