I'm having trouble with the function G:=(n)-> 3 +2n-sum(sum(f(h), a=1..floor(m/2)), m=1..n) with base case G(0):=3, where h:=2a and f(h):=sum('f(2m)*3m, m=1..(h/2 -1).

For G(1), G(2) etc I get "Error, (in type/satisfies) too many levels of recursion" , note f(h) works properly. So I think the error is from the double summation. Any ideas what may be the problem?

Any help would be greatly appreciated.