All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers > Sequences
Fade sequence (Posted on 2005-10-26) Difficulty: 4 of 5
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

See The Solution Submitted by Larry    
Rating: 3.0000 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution a solution | Comment 1 of 4
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
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (1)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (6)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2021 by Animus Pactum Consulting. All rights reserved. Privacy Information