Find the next few terms:
1,2,5,12,28,66,155,364,855,2008,4716


Hint: It's not quite Fibonacccci
more like FibonaCCcci

I played with the numbers a bit, and if we precede the series with three zeros, so that it is 0, 0, 0, 1, 2, 5, 12, ....

Then, it seems to follow that for X>4, F(X) = 2*F(X-1)+F(X-2)-F(X-4).

2 = 2*1 + 0 - 0
5 = 2*2 + 1 - 0
12 = 2*5 + 2 - 0
28 = 2*12 + 5 - 1
66 = 2*28 + 12 - 2
etc....

The next four terms would be:
11076
26013
61094
143485

-- Corrected/edited formula variable. Answer remains the same.
Edited on October 26, 2005, 2:23 pm

Posted by SilverKnight on 2005-10-26 13:26:56