lstm_autoencoder = Sequential()

# Encoder
lstm_autoencoder.add(LSTM(timesteps, activation='relu', input_shape=(timesteps, n_features), return_sequences=True))
lstm_autoencoder.add(LSTM(16, activation='relu', return_sequences=True))
lstm_autoencoder.add(LSTM(1, activation='relu'))
lstm_autoencoder.add(RepeatVector(timesteps))

# Decoder
lstm_autoencoder.add(LSTM(timesteps, activation='relu', return_sequences=True))
lstm_autoencoder.add(LSTM(16, activation='relu', return_sequences=True))
lstm_autoencoder.add(TimeDistributed(Dense(n_features)))

lstm_autoencoder.summary()