HP 38G: Better than Prime for some Sequences using the built in Sequence App

[Gerald H]

(03-07-2015 05:29 AM)BruceH Wrote:  

(03-07-2015 01:41 AM)Joe Horn Wrote:  Fascinating. The 40gs handles it fine too. I wonder why the 39gii and Prime balk at it.

It's to do with the use of U1 as the index to U1. I tried setting U2 to be U1(N-1) and making the appropriate substitution and that still fails. Creating a user defined function TT(N)=U1(N-1) and substituting also fails. So I think the Sequence app is scanning the parse tree in an effort to avoid a recursive loop and is rejecting cases that would actually work.

Explanation not correct.

Try:

U1(1)=3
U1(2)=8
U1(N)=U1(N-1)-U1(N-2)

Tickable, ticked & numerically correct!