def make_all_seqs(l):
    """
	Makes all possible sequences, including Ns, of length l
	"""
    if l > 8:
        print("Warning - large barcodes detected!")
        print("It may be faster to use option '--dont_build_reference'!")

    nts = ['A', "C", "G", "T", "N"]

    all_seqs = nts

    for i in range(l - 1):
        new_seqs = []
        for seq in all_seqs:
            for nt in nts:
                new_seqs.append(seq + nt)
        all_seqs = new_seqs

    return (all_seqs)