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Is it, or is it not? (Posted on 2007-04-10)

Is (2⁵⁸+1)/5 an integer? A prime?

See The Solution Submitted by Federico Kereki

Rating: 3.6667 (3 votes)

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re: solution --- easier nowadays

Comment 13 of 13 |

(In reply to solution by Charlie)

In the MATLAB command window:

>> digits 100

>> (vpa(2)^58+1)/5

ans =

57646075230342349.0

>> factor(ans)

ans =

[ 107367629, 536903681]

Posted by Charlie on 2020-11-23 07:15:36

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