Small challenge

[Valentin Albillo]

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Hi, J-F,

(04-22-2023 02:33 PM)J-F Garnier Wrote:  1 (easy): Can you find out the formula used to generate this series?

Yes. It took me all of 5 seconds to deduce it. According to your wishes I won't spoil it for everyone else but will give a couple of hints: (1) look at the last digit of each entry. (2) look at the sixth entry.

Quote:2 (more difficult): Can you find a HP 12-digit calculator that gives the very same and accurate results? Hint: a surprise here.

Yes. The "surprise here" may refer to the fact that the HP-71B has the next-to-last entry differ by just 1 ulp if using the default values at machine reset.

Quote:Math gurus would solve the part 1 almost immediately, but please refrain to spoil the game too quickly, until you can find which HP machine(s) can generate the very same 12-digit results for the series.

Don't worry, I won't post a solution to avoid ruining the fun, as per your request.

Thanks for the fun an best regards.
V.