The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A093162

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A093162

Primes of the form 20*R_k + 3, where R_k is the repunit (A002275) of length k.
(history; published version)

#20 by Harvey P. Dale at Mon Dec 26 16:30:17 EST 2022

STATUS

editing

approved

#19 by Harvey P. Dale at Mon Dec 26 16:30:08 EST 2022

COMMENTS

The next term (a(7)) has 95 digits. - Harvey P. Dale, Dec 26 2022

MATHEMATICA

Select[Table[FromDigits[PadLeft[{3}, n, 2]], {n, 40}], PrimeQ] (* Harvey P. Dale, Dec 26 2022 *)

STATUS

approved

editing

#18 by Joerg Arndt at Thu Jul 08 06:24:25 EDT 2021

STATUS

proposed

approved

#17 by Jon E. Schoenfield at Thu Jul 08 05:34:12 EDT 2021

STATUS

editing

proposed

#16 by Jon E. Schoenfield at Thu Jul 08 05:34:08 EDT 2021

NAME

Primes of the form 20*R_n k + 3, where R_n k is the repunit (A002275) of length nk.

CROSSREFS

Cf. A002275, A056656 (corresponding n, k, and count of digits 2 in a(n)), A096506.

STATUS

approved

editing

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

LINKS

Makoto Kamada, <a href="httphttps://stdkmd.comnet/nrr/2/22223.htm#prime">Prime numbers of the form 22...223</a>.

Discussion

Thu Jan 17

13:44

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

#14 by Ray Chandler at Sun Apr 26 12:23:29 EDT 2015

STATUS

editing

approved

#13 by Ray Chandler at Sun Apr 26 12:23:24 EDT 2015

LINKS

Makoto Kamada, <a href="http://homepage2.niftystdkmd.com/m_kamadanrr/math2/22223.htm#prime">Prime numbers of the form 22...223</a>.

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

CROSSREFS

Cf. A002275, A056656 (corresponding n, and count of digits 2 in a(n)), A096506.

STATUS

approved

editing

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

AUTHOR

_Rick L. Shepherd (rshepherd2(AT)hotmail.com), _, Mar 26 2004

Discussion

Fri Mar 30

17:36

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

#11 by Russ Cox at Fri Mar 30 17:29:15 EDT 2012

EXTENSIONS

Edited by _Ray Chandler (rayjchandler(AT)sbcglobal.net), _, Feb 27 2012

Discussion

Fri Mar 30

17:29

OEIS Server: https://oeis.org/edit/global/154