Solved by albanD in post #8 
              
              
                So for stride of 1, you have: 
padding = dilation * (kernel -1) / 2

Assuming dilation of 1 as you don’t use it in your code, you have (kernel - 1)/2. 
Since pytorch only supports padding as an integer number (what would be non-integer padding?), then you need kernel to be an odd number and you have…