A046518 Numbers with multiplicative persistence value 9.

26888999, 26889899, 26889989, 26889998, 26898899, 26898989, 26898998, 26899889, 26899898, 26899988, 26988899, 26988989, 26988998, 26989889, 26989898, 26989988, 26998889, 26998898, 26998988, 26999888, 28688999

Offset: 1

Author

Patrick De Geest, Sep 15 1998

Keywords

• nonn
• easy
• base

Examples

			26888999 -> [ 4478976 ][ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in nine steps.
		

Links

• Daniel Mondot, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Robert Israel, terms 1001..7448 from David A. Corneth)
• Eric Weisstein's World of Mathematics, Multiplicative Persistence

Crossrefs

Cf. A003001, A014120, A046509.

Programs

Maple

mp:= proc(n) option remember;
    if n <= 9 then return 0 fi;
    1+procname(convert(convert(n,base,10),`*`))
end proc:
filter:= proc(n)
  evalb(mp(convert(convert(n,base,10),`*`))=8)
end proc:
select(filter, [$26111111..29999999]); # Robert Israel, Feb 12 2019

Extensions

Offset corrected by Robert Israel, Feb 12 2019