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Revision History for A020167

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A020167

Pseudoprimes to base 39.
(history; published version)

#26 by N. J. A. Sloane at Sat Apr 01 07:56:29 EDT 2017

STATUS

reviewed

approved

#25 by Joerg Arndt at Sat Apr 01 05:11:08 EDT 2017

STATUS

proposed

reviewed

#24 by Alonso del Arte at Fri Mar 31 18:01:22 EDT 2017

STATUS

editing

proposed

#23 by Alonso del Arte at Thu Mar 30 18:22:39 EDT 2017

MATHEMATICA

max = 50003000; Select[Complement[Range[max], Prime[Range[PrimePi[max]]]], PowerMod[39, # - 1, #] == 1 &] (* Alonso del Arte, Mar 12 2017 *)

Discussion

Thu Mar 30

18:25

Alonso del Arte: My main problem is the AppendTo, but at least there isn't the shuffling of a, b, c that Orlowski likes to do. But I also object to the unnecessary global variables base and t.

#22 by Alonso del Arte at Tue Mar 28 17:21:34 EDT 2017

MATHEMATICA

max = 5000; Select[Complement[Range[max], Prime[Range[PrimePi[max]]]], PowerMod[39, # - 1, #] == 1 &] (* _T. D. Noe_, Feb 21 2012, optimized by _Alonso del Arte_, Mar 12 2017 *)

STATUS

reviewed

editing

#21 by Joerg Arndt at Mon Mar 27 10:47:36 EDT 2017

STATUS

proposed

reviewed

Discussion

Tue Mar 28

15:13

Peter Luschny: I agree with Joerg. Add your version in an independent way. If Noe's program is too convoluted or inefficient consider to propose to delete it.

#20 by Alonso del Arte at Sun Mar 26 19:13:00 EDT 2017

STATUS

editing

proposed

#19 by Alonso del Arte at Fri Mar 24 10:45:02 EDT 2017

MATHEMATICA

max = 5000; Select[Complement[Range[max], Prime[Range[PrimePi[max]]]], PowerMod[39, # - 1, #] == 1 &] (* T. D. Noe, Feb 21 2012 , optimized by _Alonso del Arte_, Mar 12 2017 *)

STATUS

proposed

editing

#18 by Robert Israel at Fri Mar 24 02:22:59 EDT 2017

STATUS

editing

proposed

#17 by Robert Israel at Fri Mar 24 02:22:51 EDT 2017

MAPLE

select(n -> 39 &^ (n-1) mod n = 1 and not isprime(n), [$2..10^5]); # Robert Israel, Mar 24 2017

STATUS

proposed

editing