Creation of a matrix (24,72) with unit lower triangular matrix?

Hello. I want to create a matrix M5(24,72) (see fig) using a unit lower triangular matrix.

Answer 1

[Matt J]

 M5 = kron(  tril(ones(24)),[1,0,0] )

[ET-TAOUSSI mehdi]

Thank you Matt J.

Answer 2

[James Tursa]

Try this (caution, untested):

M5 = zeros(24,72);
M5(:,1:3:end) = tril(ones(24,24));

[ET-TAOUSSI mehdi]

Thank you James Tursa, it works.