Graphs were generated with igraphs:

for x in range(0, 5):
    for i in [5, 10, 15, 20, 50]:
        for j in [1, 3, 5, 10]:
            g = Graph.Barabasi(i, j, directed=True)
            g.write_dot("barabasi_" + str(i) + "_" + str(j) + "_" + str(x) + ".dot")
