The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A082697

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A082697

Numbers k such that (4*10^(k-1) - 7)/3 is a plateau prime.
(history; published version)

#23 by Joerg Arndt at Mon Nov 04 02:21:32 EST 2019

STATUS

reviewed

#22 by Michel Marcus at Mon Nov 04 00:52:18 EST 2019

STATUS

proposed

#21 by Jon E. Schoenfield at Mon Nov 04 00:16:22 EST 2019

STATUS

editing

#20 by Jon E. Schoenfield at Mon Nov 04 00:16:01 EST 2019

NAME

Plateau and depression primes of the form (10^a(n)-1)/3-2*(10^(a(n)-1)+1) or (12*10^(a(n)-1)-21)/9 or 4*(10^(a(n)-1)-1)/3-1.

EXAMPLE

a(n)=7 -> (10^7-1)/3-2*(10^6+1) = 1333331.

KEYWORD

nonn,changed

STATUS

approved

#19 by Jon E. Schoenfield at Fri Oct 25 19:36:11 EDT 2019

STATUS

proposed

#18 by Jon E. Schoenfield at Fri Oct 25 19:36:01 EDT 2019

STATUS

editing

#17 by Jon E. Schoenfield at Fri Oct 25 19:35:56 EDT 2019

NAME

Plateau and depression primes of the form (10^a(n)-1)/3-2*(10^[ a(n)-1 ]+1) or (12*10^[ a(n)-1 ]-21)/9 or 4*(10^[ a(n)-1 ]-1)/3-1.

AUTHOR

Patrick De Geest, Apr 13 2003.

EXTENSIONS

a(13)=42263 from Patrick De Geest, Oct 03 2004.

STATUS

approved

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

LINKS

Makoto Kamada, <a href="http://stdkmd.com/nrr/1/13331.htm#prime">Prime numbers of the form 133...331</a>.

Discussion

Thu Jan 17

13:44

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

#15 by N. J. A. Sloane at Tue Apr 21 11:42:22 EDT 2015

LINKS

Makoto Kamada, <a href="http://mada.la.coocan.jp/nrr/1/13331.htm#prime">Prime numbers of the form 133...331</a>.

Discussion

Tue Apr 21

11:42

OEIS Server: https://oeis.org/edit/global/2424

#14 by Ray Chandler at Tue Nov 04 14:08:53 EST 2014

STATUS

editing