Talk:Weird numbers: Difference between revisions

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Perhaps some were abandoned after first-sketch exhaustive searches appeared interminably slow ?

And ~~possible~~ the references to number theory in the Perl 6 founding example could look a bit daunting to some ?

And possibly the references to number theory in the Perl 6 founding example could look a bit daunting to some ?

Here is a theoretically unambitious approach, which seems, for example, to compress the (functionally composed) Python version down to c. 300 ms for 50 weirds (about half that for 25 weirds), on a system which needs c. 24 seconds to find 25 weirds with the initial Perl 6 draft.

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# Generate the properDivisors in '''descending''' order of magnitude.

A smaller target should, I think, involve a smaller number of possible sums. The obvious candidate in an abundant number is the '''difference''' between the sum of the proper divisors and the number considered. If a sum to that difference exists, then removing the participants in ~~that~~ sum will leave a set which sums to the abundant number itself.

A smaller target should, I think, involve a smaller number of possible sums. The obvious candidate in an abundant number is the '''difference''' between the sum of the proper divisors and the number considered. If a sum to that difference exists, then removing the participants in the smaller sum will leave a set which sums to the abundant number itself.

For possible early-failing implementations of hasSum, see the Python, Haskell, JavaScript and even AppleScript drafts.