The On-Line Encyclopedia of Integer Sequences (OEIS)

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Revision History for A145746

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Showing entries 1-10 | older changes

A145746

Numbers k such that sum of the proper divisors of k is product of digits of k.
(history; published version)

#13 by Michel Marcus at Fri Jul 16 03:25:14 EDT 2021

STATUS

reviewed

approved

#12 by Joerg Arndt at Fri Jul 16 02:09:34 EDT 2021

STATUS

proposed

reviewed

#11 by Jon E. Schoenfield at Fri Jul 16 01:57:10 EDT 2021

STATUS

editing

proposed

#10 by Jon E. Schoenfield at Fri Jul 16 01:57:09 EDT 2021

NAME

Numbers n k such that sum of the proper divisors of n k is product of digits of nk.

EXAMPLE

sigma(11735953) = sigma(883*13291) = 11735953 + (13291 + 883 + 1) = 11735953 + 1*1*7*3*5*9*5*3 so 11735953 is in the sequence.

1*1*7*3*5*9*5*3 so 11735953 is in the sequence.

STATUS

approved

editing

#9 by Giovanni Resta at Thu Aug 30 15:21:56 EDT 2018

STATUS

editing

approved

#8 by Giovanni Resta at Thu Aug 30 15:21:49 EDT 2018

COMMENTS

a(5) > 2*10^12. - Giovanni Resta, Aug 30 2018

STATUS

approved

editing

#7 by Charles R Greathouse IV at Mon Nov 10 08:39:42 EST 2014

STATUS

editing

approved

#6 by Charles R Greathouse IV at Mon Nov 10 08:39:40 EST 2014

COMMENTS

All terms beyond a(3) are coprime to 6, and of course all terms are zerofree (A052382). a(5) > 2*10^1011. - Charles R Greathouse IV, Nov 03 2014

STATUS

approved

editing

#5 by Charles R Greathouse IV at Tue Nov 04 09:11:04 EST 2014

STATUS

editing

approved

#4 by Charles R Greathouse IV at Tue Nov 04 09:11:01 EST 2014

COMMENTS

All terms beyond a(3) are coprime to 6, and of course all terms are zerofree (A052382). a(5) > 2*10^910. - Charles R Greathouse IV, Nov 03 2014