The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A362429 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A362429

Smallest k such that the concatenation of the numbers 123...k in base n is prime when interpreted as a decimal number, or -1 if no such prime exists.
(history; published version)

#33 by N. J. A. Sloane at Mon Sep 16 12:38:54 EDT 2024

STATUS

proposed

approved

#32 by Michael S. Branicky at Mon Sep 16 12:34:36 EDT 2024

STATUS

editing

proposed

#31 by Michael S. Branicky at Mon Sep 16 12:33:46 EDT 2024

CROSSREFS

Cf. A376221.

STATUS

approved

editing

#30 by Joerg Arndt at Sun Jul 30 01:35:06 EDT 2023

STATUS

reviewed

approved

#29 by Michel Marcus at Sun Jul 30 01:14:30 EDT 2023

STATUS

proposed

reviewed

#28 by Jon E. Schoenfield at Sun Jul 30 00:01:16 EDT 2023

STATUS

editing

proposed

#27 by Jon E. Schoenfield at Sun Jul 30 00:01:08 EDT 2023

COMMENTS

It If it exists, a(10) would be the index of the first prime in A007908. See A007908 for the latest information about the search for this prime.

STATUS

approved

editing

#26 by N. J. A. Sloane at Thu Apr 20 20:34:46 EDT 2023

STATUS

proposed

approved

#25 by Michael S. Branicky at Thu Apr 20 18:51:42 EDT 2023

STATUS

editing

proposed

#24 by Michael S. Branicky at Thu Apr 20 18:51:40 EDT 2023

COMMENTS

a(710), ..., a(14) are respectively 22, 227, 127, ?, 144, 307, ?, 25.

a(6), a(10), and a(13) are presently unknown. a(6) > 12000 and a(13) > 10000 if they are it is not -1.