I agree with you. Nevertheles, here is a partial answer to Raman question. If take a simpler recurrence than yours
1) a_0 = 0, a_1 = 1, b_0 = 1 and b_1 = 0 2) for n >= 0, a_{n+1} = 2 * a_n + b_n and b_{n+2} = a_n + 3 * b_n @cached_function def a(n): if n == 0: return 0 elif n == 1: return 1 else: return 2*a(n-1) + b(n-1) @cached_function def b(n): if n == 0: return 1 elif n == 1: return 0 else: return a(n-1) + 3*b(n-1) Then running sage you obtain sage: a(10) 29375 sage: b(10) 47500 The advantage of having cached_function is that each result is stored while you do not have to take care about it! It is also possible to adapt your maple code but this recursive version is much more compact. Vincent -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/groups/opt_out.