Try
seed_text = "Laurence went to dublin"
next_words = 100
for _ in range(next_words):
token_list = tokenizer.texts_to_sequences([seed_text])[0]
token_list = pad_sequences([token_list], maxlen=max_sequence_len-1, padding='pre')
index = np.argmax(model.predict(token_list, verbose=0))
output_word = tokenizer.index_word[index]
seed_text += " " + output_word
print(seed_text)