interpolatory spline, Numerical solution of boundary value problems involving ordinary differential equations, numerical examples, convergence, algorithm, End conditions, boundary value problems, Interpolatory spline, Applied Mathematics, error bound, comparison of methods, consistency relations, Consistency relations, Boundary value problems, Computational Mathematics, Sextic spline, sextic spline, Septic spline, septic spline, Error bound, Linear boundary value problems for ordinary differential equations, end conditions, Stability and convergence of numerical methods for ordinary differential equations