login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A046516 Numbers with multiplicative persistence value 7. 5
68889, 68898, 68988, 69888, 86889, 86898, 86988, 88689, 88698, 88869, 88896, 88968, 88986, 89688, 89868, 89886, 96888, 98688, 98868, 98886, 168889, 168898, 168988, 169888, 186889, 186898, 186988, 188689, 188698, 188869, 188896, 188968 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
From Daniel Mondot, Mar 26 2022: (Start)
The product of the digits of each term is 27648, 47628, 64827, 84672, 134217728, 914838624, 1792336896, 3699376128, 48814981614, 134481277728, 147483721728 or 1438916737499136 (sequence A350185).
The first 62 terms produce 27648.
The first term that produces 47628 is a(63).
The first term that produces 64827 is a(233).
The first term that produces 84672 is a(235).
The first term that produces 134217728 is a(1753110).
The first term that produces 914838624 is a(17835449).
The first term that produces 1792336896 is a(18235677).
The first term that produces 3699376128 is a(23853261).
The first term that produces 48814981614 is a(66441891).
The first term that produces 134481277728 is a(452601087).
The first term that produces 147483721728 is a(425636434).
The first term that produces 1438916737499136 is somewhere after a(500*10^6). (End)
LINKS
Eric Weisstein's World of Mathematics, Multiplicative Persistence
EXAMPLE
68889 -> [ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in seven steps.
MAPLE
mp:= proc(n) option remember;
if n <= 9 then return 0 fi;
1+procname(convert(convert(n, base, 10), `*`))
end proc:
select(mp=7, [$1..200000]); # Robert Israel, Feb 12 2019
CROSSREFS
Sequence in context: A213702 A233721 A121107 * A199997 A250500 A354194
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Sep 15 1998
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 12 06:13 EDT 2024. Contains 371623 sequences. (Running on oeis4.)