[seqfan] Re: A program to compute A002845

[bacher]

Are there any identities not coming from
((2^2)^2)=(2^(2^2)) among such expressions?

Best wishes, Roland Bacher


Vladimir Reshetnikov <v.reshetnikov at gmail.com> a écrit :

> Today I published a program on GitHub that computes elements of
> https://oeis.org/A002845 (Number of distinct values taken by 2^2^...^2,
> with n 2's and parentheses inserted in all possible ways).
>
> https://github.com/VladimirReshetnikov/Oeis.A002845
>
> It uses a special representation of numbers that allows to efficiently
> manipulate high power towers, but is still brute force in the sense that it
> enumerates and stores all possible outcomes for each n. So far I was able
> to confirm all values currently listed (up to n=27), and I estimate that I
> would need a machine with more than 100GB RAM to compute the next.
>
> I would be delighted if anybody could improve my solution, port it to other
> programming languages, or provide computational resources.
>
> --
> Best regards
> Vladimir Reshetnikov
>
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