Hi, sorry, one more quick question. Why does Maple complain about something like this, using n as above,

f:=int(sin(t*y*x^n)/exp(x),x=0..1,y=0..1);

series(f,t);

It likes it if you take out the y-variable and only integrate the x, but with the y as above, it complains that there are invalid terms in the series.

Thank you very much guys, you're both really fast. :)

Thanks, but now if I plug that into seriestodiffeq of the gfun package, it complains that it's not a series.

Oops, let me try that again (sorry - new to the forum as well).

I'm trying to do something like this:

assume(n,'integer'):series(x^n*exp(x),x);

and Maple complains. I eventually want to use seriestodiffeq with the result (not this exact expression - this is just an example), but I can't because of the error. Is there another way of doing this? Any help is appreciated. Thanks!