documentclass{article}
usepackage{amsmath}

begin{document}
begin{equation*}
    mathbf{H}=
    begin{pmatrix}
        1 & 2 & 3 & 5\
        1 & 1 & 4 & 2\
        4 & 1 & 2 & 4
    end{pmatrix}
   end{equation*}
end{document}