N = regular_sequence.size
offset_arr = np.cumsum(lag_seq)
idx = np.arange(offset_arr.size) * N + offset_arr
out = np.zeros(idx.max() + N, dtype=regular_sequence.dtype)
np.put(out, idx[:, (None)] + np.arange(N), regular_sequence)
Generate 1d numpy with chunks of random length