The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A093177 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A093177

Primes of the form 90*R_k + 1, where R_k is the repunit (A002275) of length k.
(history; published version)

#19 by Joerg Arndt at Thu Jul 08 06:24:19 EDT 2021

STATUS

proposed

approved

#18 by Jon E. Schoenfield at Thu Jul 08 05:35:26 EDT 2021

STATUS

editing

proposed

#17 by Jon E. Schoenfield at Thu Jul 08 05:35:24 EDT 2021

NAME

Primes of the form 90*R_n k + 1, where R_n k is the repunit (A002275) of length nk.

COMMENTS

Primes of the form 10^nk - 9 (nk=3,5,7,...). - Vincenzo Librandi, Nov 16 2010

CROSSREFS

Cf. A056696 (corresponding nk), A095714.

STATUS

approved

editing

#16 by Charles R Greathouse IV at Thu Jan 17 13:44:06 EST 2019

LINKS

Makoto Kamada, <a href="httphttps://stdkmd.comnet/nrr/9/99991.htm#prime">Prime numbers of the form 99...991</a>.

Discussion

Thu Jan 17

13:44

OEIS Server: https://oeis.org/edit/global/2791

#15 by Susanna Cuyler at Tue Jan 16 21:56:15 EST 2018

STATUS

proposed

approved

#14 by Jon E. Schoenfield at Tue Jan 16 17:07:00 EST 2018

STATUS

editing

proposed

#13 by Jon E. Schoenfield at Tue Jan 16 17:06:57 EST 2018

COMMENTS

Primes of the form 10^n-9 (n=3,5,7,..,.) [From . - _Vincenzo Librandi, _, Nov 16 2010]

STATUS

approved

editing

#12 by Ray Chandler at Mon Apr 27 09:03:31 EDT 2015

STATUS

editing

approved

#11 by Ray Chandler at Mon Apr 27 09:03:27 EDT 2015

LINKS

Makoto Kamada, <a href="http://homepage2.niftystdkmd.com/m_kamadanrr/math9/99991.htm#prime">Prime numbers of the form 99...991</a>.

<a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>

STATUS

approved

editing

#10 by Russ Cox at Fri Mar 30 17:36:41 EDT 2012

AUTHOR

_Rick L. Shepherd (rshepherd2(AT)hotmail.com), _, Mar 27 2004

Discussion

Fri Mar 30

17:36

OEIS Server: https://oeis.org/edit/global/176