The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A281276 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A281276

Numbers k such that (2*10^k + 457)/9 is prime.
(history; published version)

#12 by Michael De Vlieger at Fri Jun 07 23:59:08 EDT 2024

STATUS

proposed

approved

#11 by Jon E. Schoenfield at Fri Jun 07 23:35:51 EDT 2024

STATUS

editing

proposed

#10 by Jon E. Schoenfield at Fri Jun 07 23:35:49 EDT 2024

COMMENTS

For k > 2, numbers k such that k-2 occurrences of the digit 2 followed by the digits 73 is prime (see Example section).

LINKS

Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/primedifficultyprime_difficulty.txt">Search for 2w73.</a>.

EXAMPLE

Initial terms and primes associated primes:

STATUS

approved

editing

#9 by Charles R Greathouse IV at Thu Jan 17 13:44:09 EST 2019

LINKS

Makoto Kamada, <a href="httphttps://stdkmd.comnet/nrr">Factorization of near-repdigit-related numbers</a>.

Makoto Kamada, <a href="httphttps://stdkmd.comnet/nrr/prime/primedifficulty.txt">Search for 2w73.</a>

Discussion

Thu Jan 17

13:44

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

#8 by Peter Luschny at Mon Jan 08 12:21:33 EST 2018

STATUS

reviewed

approved

#7 by Michel Marcus at Mon Jan 08 11:17:52 EST 2018

STATUS

proposed

reviewed

#6 by Robert Price at Mon Jan 08 10:28:51 EST 2018

STATUS

editing

proposed

#5 by Robert Price at Mon Jan 08 10:28:16 EST 2018

DATA

1, 2, 4, 5, 7, 8, 11, 13, 20, 22, 38, 47, 76, 269, 299, 527, 724, 1214, 2243, 2327, 12635, 15064, 28921, 34303, 49117, 58151, 89279, 199283

COMMENTS

a(2829) > 2*10^5.

EXTENSIONS

a(28) from Robert Price, Jan 08 2018

STATUS

approved

editing

#4 by N. J. A. Sloane at Wed Jan 18 21:38:05 EST 2017

STATUS

proposed

approved

#3 by Robert Price at Wed Jan 18 18:01:22 EST 2017

STATUS

editing

proposed