function A = golub(n)
%GOLUB  generate a special random integer test matrix
%
%   GOLUB(n) is the product of two random integer n-by-n matrices,
%   one of them unit lower triangular and one unit upper triangular.
%
%   Copyright 2014 Cleve Moler

    s = 10;
    L = tril(round(s*randn(n)),-1) + eye(n);
    U = triu(round(s*randn(n)),1) + eye(n);
    A = L*U;
end
