The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A296094 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A296094

Numbers k such that (43*10^k + 47)/9 is prime.
(history; published version)

#12 by Joerg Arndt at Thu May 02 04:27:39 EDT 2024

STATUS

proposed

approved

#11 by Jon E. Schoenfield at Thu May 02 04:09:49 EDT 2024

STATUS

editing

proposed

#10 by Jon E. Schoenfield at Thu May 02 04:09:47 EDT 2024

COMMENTS

For k > 1, numbers k such that the digit 4 followed by k-2 occurrences of the digit 7 followed by the digits 83 is prime (see Example section).

LINKS

Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/primedifficultyprime_difficulty.txt">Search for 47w83</a>.

EXAMPLE

Initial terms and primes associated primes:

STATUS

approved

editing

#9 by Charles R Greathouse IV at Thu Jan 17 13:44:10 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 47w83</a>

Discussion

Thu Jan 17

13:44

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

#8 by Ray Chandler at Sat Dec 01 11:12:18 EST 2018

STATUS

reviewed

approved

#7 by Michel Marcus at Sat Dec 01 11:01:57 EST 2018

STATUS

proposed

reviewed

#6 by Robert Price at Sat Dec 01 11:00:51 EST 2018

STATUS

editing

proposed

#5 by Robert Price at Sat Dec 01 11:00:47 EST 2018

DATA

1, 3, 7, 12, 15, 21, 85, 177, 204, 477, 487, 1686, 2179, 2815, 2892, 3466, 7308, 17883, 25431, 69048, 89169, 126441

COMMENTS

a(2223) > 2*10^5.

EXTENSIONS

a(22) from Robert Price, Dec 01 2018

STATUS

approved

editing

#4 by Susanna Cuyler at Mon Dec 04 18:35:41 EST 2017

STATUS

proposed

approved

#3 by Robert Price at Mon Dec 04 12:21:57 EST 2017

STATUS

editing

proposed