The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A036309 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A036309

Composite numbers whose prime factors contain no digits other than 1 and 9.
(history; published version)

#29 by Joerg Arndt at Wed May 18 07:56:20 EDT 2022

STATUS

reviewed

approved

#28 by Michel Marcus at Wed May 18 02:27:48 EDT 2022

STATUS

proposed

reviewed

#27 by Amiram Eldar at Wed May 18 02:11:45 EDT 2022

STATUS

editing

proposed

#26 by Amiram Eldar at Wed May 18 02:09:12 EDT 2022

LINKS

<a href="/index/Pri#prime_factors">Index entries for sequences related to prime factors</a>.

#25 by Amiram Eldar at Wed May 18 02:05:41 EDT 2022

FORMULA

Sum_{n>=1} 1/a(n) = Product_{p in A020457} (p/(p - 1)) - Sum_{p in A020457} 1/p - 1 = 0.0200389643... . - Amiram Eldar, May 18 2022

STATUS

approved

editing

#24 by Andrew Howroyd at Sat Jun 19 22:39:24 EDT 2021

STATUS

proposed

approved

#23 by Jon E. Schoenfield at Sat Jun 19 22:26:12 EDT 2021

STATUS

editing

proposed

#22 by Jon E. Schoenfield at Sat Jun 19 22:26:10 EDT 2021

NAME

Composite numbers n such that digits of whose prime factors of n are either contain no digits other than 1 or and 9.

STATUS

approved

editing

#21 by OEIS Server at Sun Oct 18 15:50:03 EDT 2020

LINKS

David A. Corneth, <a href="/A036309/b036309_1.txt">Table of n, a(n) for n = 1..10000</a> (first 360 terms from Harvey P. Dale)

#20 by N. J. A. Sloane at Sun Oct 18 15:50:02 EDT 2020

STATUS

proposed

approved

Discussion

Sun Oct 18

15:50

OEIS Server: Installed new b-file as b036309.txt.  Old b-file is now b036309_1.txt.