HP 25 Fibonacci sequence in one program step

10142021, 10:03 AM
(This post was last modified: 10142021 10:05 AM by C.Ret.)
Post: #21




RE: HP 25 Fibonacci sequence in one program step
(10132021 04:42 PM)Gerson W. Barbosa Wrote: RPN: Y, Z, T < k1; X <k2 Then * * * … and Thank to remind me this old matrix arithmetic multiplication on RPL. I remember a few decade when I try to use power exponentiation of [[1 1][1 0]] to the n to directly get Fn value. Hard time discovering sadly that the matrix exponentiation on the HP28C/S doesn't work with ^ instruction. (10132021 06:26 PM)Dave Britten Wrote: I think you guys have figured out the gist of it. OK, now I can publish my completed trace print. [attachment=9914] (10132021 07:35 PM)David Hayden Wrote:(10132021 07:11 PM)Gerson W. Barbosa Wrote: 0 1 + Then repeat RCL + ST LThat's it! I can't applied this trick neither on my HP41C that miss memory recall arithmetic, nor on my HP15C who have recall arithmetic but no stack register manipulation. The amazing HP 42S (or succedanea DM 42S or Free 42) is really a blend of the two anthology systems. At least, like the HP25, the HP41 and HP15C need a two steps naked program « LASTx + », close to a simple RPL code leaving the Fibonacci sequence reversed in the stack initiate by 1 DUP and repeating « OVER OVER + » over and over... 

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