Dont put your LSTM in Sequential, it wont work.
See the documentation of LSTM for why it wont work: http://pytorch.org/docs/0.3.0/nn.html#torch.nn.LSTM 82 the input to LSTM has to be a tuple of Variables, but you are only passing a single Variable.
The output of LSTM is a tuple of Variables, but the input to ReLU is a Variable (not a tuple of Variables)