Wikipedia:Reference desk/Archives/Mathematics/2010 December 26

= December 26 =

Reference request for certain linear sequences of functions.
Hi all. I think I read somewhere in Wikipedia a name, and perhaps a reference, for sequences of functions satisfying a linear recurrence of the following form


 * $$ f_{k+1}(x)=a(x)f_k'(x)$$

where each term is the derivative of the preceding one, times a fixed function $$a(x)$$. Does anybody have a clue? I'm not able to find it again.... --pm a 09:37, 26 December 2010 (UTC)


 * Strangely Chapter 22 of Abramowitz-Stegun mentions no relations of this form of the notable sequences of orthogonal polynomials. &#x2013; b_jonas 10:39, 26 December 2010 (UTC)