Solved by pramod.srinivasan in post #2 
              
              
                From the function of definition for nn.conv1d 
torch.nn.Conv1d(in_channels, out_channels, kernel_size, stride=1, padding=0, dilation=1, groups=1, bias=True, padding_mode='zeros')

C_in = 1, 
C_out = 1, 
K  = 3 
S = 1 
P = 0 
From the slide 63 of lecture 5, cs231n, the size of the L(A) : 1 X 5 X 1 
S…