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Old 2019-05-13, 12:31   #1
enzocreti
 
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Default F(33) Fermat 33-th

is there any software available (for "normal" human beings) that could verify the 33-th Fermat number for primality at least in principle ?
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Old 2019-05-13, 12:52   #2
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Quote:
Originally Posted by enzocreti View Post
is there any software available (for "normal" human beings) that could verify the 33-th Fermat number for primality at least in principle ?
Yes, in principle, as long as you are prepared to wait for a few millennia for the answer.
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Old 2019-05-13, 18:53   #3
ixfd64
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Ernst's thread may be of interest: https://mersenneforum.org/showthread.php?t=18748
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Old 2019-05-13, 19:04   #4
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Quote:
Originally Posted by xilman View Post
Yes, in principle, as long as you are prepared to wait for a few millennia for the answer.
That is hardly a normal person. Or maybe you know something you aren't revealing?

:link to a vid of Queen's "Who wants to live forever?":
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Old 2019-05-13, 19:22   #5
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Right now I estimate that it's possible to do a 2^33-bit convolution in about 250ms on a high-end computer. So that's 4 iter/sec.

2^33 iterations would be 2^31 seconds or about 63 years.

So not quite a few millennia, but not something we'd want to try now.

Last fiddled with by Mysticial on 2019-05-13 at 19:39
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Old 2019-05-14, 02:25   #6
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Quote:
Originally Posted by Mysticial View Post
2^33 iterations would be 2^31 seconds or about 63 years.
Did you do this conversion in your head? Because I get 68 years (with a calculator, natch).
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Old 2019-05-14, 04:40   #7
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We know (from the past, when we implemented timers and other things in electronic toys we produce here) that there are about 2^25 seconds in an year. So, without calculator, I would have said in a blink, 64 years (31-25=6, 2^6=64).
But the result is indeed 68 (checked axn with my super-accurate windows 7 calcuator, he is lucky this time, I mean axn, not the calculator, I didn't catch him with the wrong answer, but my time will come... hehe)

Last fiddled with by LaurV on 2019-05-14 at 04:43
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Old 2019-05-14, 06:17   #8
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Quote:
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Did you do this conversion in your head? Because I get 68 years (with a calculator, natch).

No, but I got lazy and used 8 billion instead of 2^33.
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Old 2019-05-14, 06:52   #9
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Quote:
Originally Posted by Mysticial View Post
No, but I got lazy and used 8 billion instead of 2^33.
An interesting mnemonic device for me is 1 year =Ο€ *107 seconds.

Actual number is 3.1577*107
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Old 2019-05-14, 12:59   #10
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Quote:
Originally Posted by rudy235 View Post
An interesting mnemonic device for me is 1 year =Ο€ *107 seconds.

Actual number is 3.1577*107
Actually it is 3.1536*107 or 3.16224*107 for leap year or 3.15576*107 for 4-year average.

Last fiddled with by ATH on 2019-05-14 at 12:59
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Old 2019-05-14, 15:52   #11
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Quote:
Originally Posted by rudy235 View Post
An interesting mnemonic device for me is 1 year =Ο€ *107 seconds.

Actual number is 3.1577*107
Quote:
Originally Posted by ATH View Post
Actually it is 3.1536*107 or 3.16224*107 for leap year or 3.15576*107 for 4-year average.
1 Year = (365 + 97/400) days
1 day =86,400 seconds


(365+97/400)*86400 =3.1557 * 107

=0.45% over Ο€*107
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