Talk:Untouchable numbers: Difference between revisions
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m (→reduction in the number of (counting) ranges: check if limit*factor with factor = limit^(1/3)) |
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I've reduced the number of ranges for counting untouchable numbers. It seems the upper limit for searching for touchable numbers was far higher than I guesstimated. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 09:28, 9 February 2021 (UTC) |
I've reduced the number of ranges for counting untouchable numbers. It seems the upper limit for searching for touchable numbers was far higher than I guesstimated. -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 09:28, 9 February 2021 (UTC) |
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:I have checked counting ranges, but, as Nigel stated , that's not the way to get an reliable result, when changing the upper limit. |
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<pre> |
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Limit //100*1000*1000;//10*1000*1000;//5*1000*1000;//1000*1000; |
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factor //384( to small ) ;//152;//104;//64; // search area = factor*Limit</pre> |
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:How about using Goldbach conjectue ( tested true > 1e18 ).All numbers a sum of max three primes<BR> |
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proper div sum(p*q) = 1+p+q / p<>q and both prime and p*q <Limit |
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proper div sum(p*q*r) = 1+p+q+r+p*q+p*r+q*r/ p<>q<>r and all prime and p*q*r <Limit |
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: is limit for checks == limit^(1/3) |
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: I'll test it with 1e8 and factor 464 will take ~30min |
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== Number of untouchable numbers up to 1 million == |
== Number of untouchable numbers up to 1 million == |