On the analytic solution of the Cauchy problem

Xiang-dong Hou
2008 Proceedings of the American Mathematical Society  
Derivatives of a solution of an ODE Cauchy problem can be computed inductively using the Faà di Bruno formula. In this paper, we exhibit a noninductive formula for these derivatives. At the heart of this formula is a combinatorial problem, which is solved in this paper. We also give a more tractable form of the Magnus expansion for the solution of a homogeneous linear ODE.
doi:10.1090/s0002-9939-08-09493-8 fatcat:ydd4jjqdjjewxl52wn4jqiegyi