Brilliant! I've solved the problem now, thank you so much. But please tell me, how did you possibly know to do that? That was not obvious to me at all, and I'm not sure how you would just know to do that.hi jdinatale!
in the third line you have ∑k=0…j j+1Ck+1
put m = k+1, that's ∑m=1…j+1 j+1Cm …
what is that?