I tried your code and PyTorch 0.3.1 complained that the LSTM input didn’t have 3 dimensions.
It looks like the lstm took your input of shape (13,10) and unsqueezed it to (13,10,1) and then broadcasted it to (13,10,10). That means that it was interpreting the 2D input as 10 sequences of length 13 containing 10 features at each timestep BUT those 10 features all contained identical values. This makes no sense, so the output makes no sense either.