I need some help writing the recurrence relation fro this problem, or problem 30, since they are very similar. I've worked out some solutions and this is what I've got:
a1 = 0
a2 = 0
a3 = 1
a4 = 1 + 1
a5 = 2 + 1 + 2
a6 = 4 + 2 + 2 + 4
a7 = 8 + 4 + 4 + 4 + 8
So, from here I can't find the sequence that gives me those numbers. I believe what's above is right, but if it isn't or there is a better way to look at it, let me know. Thanks for the help. --Aoser 17:09, 15 October 2008 (UTC)