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Revision History for A126659

(Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A126659 Least number k > 0 such that ((2n-1)^k + 1)/(2n) is prime, or 0 if no such prime exists.
(history; published version)
#22 by Susanna Cuyler at Fri Mar 29 21:06:59 EDT 2019
STATUS

reviewed

approved

#21 by Michel Marcus at Fri Mar 29 13:58:05 EDT 2019
STATUS

proposed

reviewed

#20 by Robert Price at Fri Mar 29 13:28:58 EDT 2019
STATUS

editing

proposed

#19 by Robert Price at Fri Mar 29 13:28:55 EDT 2019
COMMENTS

a(49) > 143800. - Robert Price, Mar 29 2019

MATHEMATICA

A126659[n_] := Module[{k = 1}, If[n == 14, Return[0]]; While[! PrimeQ[((2 n - 1)^k + 1)/(2 n)], k++]; k]; Join[Table[A126659[n], {n, 2, 48}]] (* _}] (* _Robert Price_, Oct 29 2018 *)

STATUS

approved

editing

#18 by N. J. A. Sloane at Sat Dec 01 08:02:14 EST 2018
STATUS

proposed

approved

#17 by Michel Marcus at Fri Nov 30 01:46:25 EST 2018
STATUS

editing

proposed

#16 by Michel Marcus at Fri Nov 30 01:46:17 EST 2018
PROG

(PARI) a(n) = {if ((p=ispower(2* (n-1)) && (p>2), ==14, return(0)); my(k=3); while (! isprime(((2*n-1)^k + 1)/(2*n)), k = nextprime(k+1)); k; } \\ Michel Marcus, Nov 23 2018

STATUS

proposed

editing

#15 by Michel Marcus at Fri Nov 23 04:00:23 EST 2018
STATUS

editing

proposed

Discussion
Fri Nov 30 01:45
Michel Marcus: Robert warned me that this is not ok for n=41
#14 by Michel Marcus at Fri Nov 23 03:59:37 EST 2018
PROG

(PARI) a(n) = {if ((p=ispower(2*n-1)) && (p>2), return(0)); my(k=3); while (! isprime(((2*n-1)^k + 1)/(2*n)), k = nextprime(k+1)); k; } \\ Michel Marcus, Nov 23 2018

STATUS

approved

editing

Discussion
Fri Nov 23 04:00
Michel Marcus: I think rather (p=ispower(2*n-1)) && (p>2) than n=14 : See 1st comment of A084742.
#13 by Susanna Cuyler at Tue Oct 30 20:19:30 EDT 2018
STATUS

proposed

approved

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Last modified September 14 12:31 EDT 2024. Contains 375921 sequences. (Running on oeis4.)