confused about dimensions of detailed cofficients when apply db3 of level 6

I have a cell array comprises of three cell with dimension of 868 by 16 of each cell. When i apply db3 with level 6 on each cell and safe detailed coefficient and approximate coefficient in an array corresponding to original data cells by using Matlab code shown below:

dwt_coeffs_struct = struct('A', cell(size(data)), 'D', cell(size(data)));

% Loop over each cell in the data array

for i = 1:numel(data)

% Convert the cell data to double and reshape it to a column vector

signal = reshape(cell2mat(data{i}), [], 1);

% Initialize arrays to store approximation coefficients and detail coefficients

A_coeffs = cell(1, 6);

D_coeffs = cell(1, 6);

% Perform the DWT for each level

for j = 1:6

[C, L] = wavedec(signal, j, 'db3');

% Store the approximation coefficients and detail coefficients separately

if j == 1

A_coeffs{j} = appcoef(C, L, 'db3', j);

end

D_coeffs{j} = detcoef(C, L, j);

end

% Store the DWT coefficients for this signal in the structure array

dwt_coeffs_struct(i).A = A_coeffs;

dwt_coeffs_struct(i).D = D_coeffs;

end

Than i got detiled cofficents D1=41666 by 1

D2=20835 by 1

D3=10420 by 1

D4=5212 by 1

D5=2608 by 1

D6=1306 by 1

Am i getting correct dimensions of these detailed coffinites ....Please guide so that i may further extract features from these detailed coefficients