login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A046516 Numbers with multiplicative persistence value 7. 3
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

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

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

Cf. A003001, A014120, A046507.

Sequence in context: A213702 A233721 A121107 * A199997 A250500 A096551

Adjacent sequences:  A046513 A046514 A046515 * A046517 A046518 A046519

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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 15 03:16 EDT 2021. Contains 343909 sequences. (Running on oeis4.)