perplexus.info :: Sequences : Seventh Term Settlement

Seventh Term Settlement (Posted on 2016-07-22)

Each of A(1), A(2),..., A(7) is a positive integer such that:

(i) A(6) = 144, and

(ii) A(n+3) = A(n+2)(A(n+1)+A(n)), for n = 1,2,3,4

Find A(7)

See The Solution Submitted by K Sengupta

Rating: 5.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

no bad equations

| Comment 6 of 10 |

Calling the first 3 terms x,y,z to minimize the use of parentheses and subscripts and building up the next terms I get A(6) = 144 = z^2 * (x+y)(x+y+1)(y+z), making z=12,6,4,3,2,1.

The first two values are too big, the next two don't give a result containing factors that are consecutive, and the last two give the previously cited answers: (x,y,z) = (2,1,2) and (7,1,1).

Posted by xdog on 2016-07-22 12:41:08

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:


perplexus dot info