Little explorations with HP calculators (no Prime)

[John Keith]

(01-13-2019 05:05 PM)DavidM Wrote:  I didn't attempt to apply any symbolic analysis first, as my limited "toolbox" in that regard didn't offer any obvious hints.

Seeing the problem description did, though. So I came up with the following code to produce the numeric result:


The code assumes the initial list is already on the stack before execution. Although I didn't look at the other solutions before putting this together, it does bear a striking resemblance to Thomas' approach.

I just looked at this thread, and (un)surprisingly my program was exactly the same as yours.

The result is the 8th term of A064320, the description of which is very similar to Thomas's derivation. Many interesting ideas here!

Additionally, the same operation with + instead of * yields A001792.