Hi Stephan,
As per my understanding, you want to have the Alpert multiwavelets of any order, say 'K ‘, and you want a set of functions for that.
I have attached a file exchange link that supports this operation, which contains many functions that might be relevant for your use case.
The function "get_Alpert_multiwavelet" can be used to generate Alpert's multiwavelets with positive first coefficients.
You can display them using "plot_Alpert_multiwavelet.m."
One thing to note is that this is only supported on the Windows platform.
I hope this was helpful.