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

[Gerald H]

(03-07-2015 10:28 AM)Thomas Ritschel Wrote:  

(03-07-2015 10:07 AM)Thomas Ritschel Wrote:  Anyway, even in HOME view on the 39gII it already takes about 20 seconds to compute TT(15). For larger arguments it doesn't finish in reasonable time...

Edit: For TT(20) it takes about 11 minutes!

There is a significant speed-up if one changes the ELSE case into:

Code:

    LOCAL TT1:=TT(n-1);
    RETURN(TT(TT1)+TT(n-TT1));

Now one gets TT(20) almost immediately and TT(40) in just 7 seconds...

Still won't work on Prime.