Optimal (v, 4, 2, 1) optical orthogonal codes (OOC) with v<=75 and v=71 are classified up to equivalence. One (v,4,2,1) OOC is presented for all v≤181, for which an optimal OOC exists.
Cite
@article{arxiv.1003.6013,
title = {Optimal (v, 4, 2, 1) optical orthogonal codes with small parameters},
author = {Tsonka Baicheva and Svetlana Topalova},
journal= {arXiv preprint arXiv:1003.6013},
year = {2011}
}