def _dict_seq_locus(list_c, loci_obj, seq_obj):
    """
    return dict with sequences = [ cluster1, cluster2 ...]
    """
    seqs = defaultdict(set)
    # n = len(list_c.keys())
    for c in list_c.values():
        for l in c.loci2seq:
            [seqs[s].add(c.id) for s in c.loci2seq[l]]

    common = [s for s in seqs if len(seqs[s]) > 1]
    seqs_in_c = defaultdict(float)
    for c in list_c.values():
        for l in c.loci2seq:
            # total = sum([v for v in loci_obj[l].coverage.values()])
            for s in c.loci2seq[l]:
                if s in common:
                    pos = seq_obj[s].pos[l]
                    # cov = 1.0 * loci_obj[l].coverage[pos] / total
                    cov = 1.0 * loci_obj[l].coverage[pos]
                    if seqs_in_c[(s, c.id)] < cov:
                        seqs_in_c[(s, c.id)] = cov
    seqs_in_c = _transform(seqs_in_c)
    return seqs_in_c
return dict with sequences = [ cluster1, cluster2 ...]