The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A001770 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A001770

Numbers k such that 5*2^k - 1 is prime.
(history; published version)

#39 by Alois P. Heinz at Sat Dec 22 14:40:44 EST 2018

STATUS

reviewed

approved

#38 by Michel Marcus at Sat Dec 22 14:15:48 EST 2018

STATUS

proposed

reviewed

#37 by Robert Price at Sat Dec 22 13:32:39 EST 2018

STATUS

editing

proposed

#36 by Robert Price at Sat Dec 22 13:32:09 EST 2018

NAME

Numbers n k such that 5*2^n k - 1 is prime.

DATA

2, 4, 8, 10, 12, 14, 18, 32, 48, 54, 72, 148, 184, 248, 270, 274, 420, 1340, 1438, 1522, 1638, 1754, 1884, 2014, 2170, 2548, 2622, 2652, 2704, 13510, 21738, 25624, 41934, 51478, 52540, 53230, 172300, 245728, 350028, 1194164

KEYWORD

nonn,nice,hard,changed,more

EXTENSIONS

a(40) from the Wilfrid Keller link by Robert Price, Dec 22 2018

STATUS

approved

editing

#35 by N. J. A. Sloane at Wed Dec 12 07:58:04 EST 2018

LINKS

Wilfrid Keller, <a href="http://web.archive.org/web/20161028021640/http://www.prothsearch.netcom/riesel2.html">List of primes k.2^n - 1 for k < 300</a>

Discussion

Wed Dec 12

07:58

OEIS Server: https://oeis.org/edit/global/2776

#34 by N. J. A. Sloane at Thu Mar 02 11:36:05 EST 2017

LINKS

Wilfrid Keller, <a href="http://web.archive.org/web/20161028021640/http://www.prothsearch.net/riesel2.html">List of primes k.2^n - 1 for k < 300</a>

Discussion

Thu Mar 02

11:36

OEIS Server: https://oeis.org/edit/global/2606

#33 by Charles R Greathouse IV at Tue Feb 07 18:06:53 EST 2017

STATUS

editing

approved

#32 by Charles R Greathouse IV at Tue Feb 07 18:06:50 EST 2017

PROG

(PARI) is(n)=isprime(5*2^n-1) \\ Charles R Greathouse IV, Feb 07 2017

STATUS

approved

editing

#31 by Vaclav Kotesovec at Wed Oct 15 14:22:44 EDT 2014

STATUS

proposed

approved

#30 by Wesley Ivan Hurt at Wed Oct 15 14:00:16 EDT 2014

STATUS

editing

proposed