A046517 Numbers with multiplicative persistence value 8.
2677889, 2677898, 2677988, 2678789, 2678798, 2678879, 2678897, 2678978, 2678987, 2679788, 2679878, 2679887, 2687789, 2687798, 2687879, 2687897, 2687978, 2687987, 2688779, 2688797, 2688977, 2689778, 2689787, 2689877
Offset: 1
Examples
2677889 -> [ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in eight steps.
Links
- Daniel Mondot, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Robert Israel)
- Eric Weisstein's World of Mathematics, Multiplicative Persistence
Programs
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Maple
mp:= proc(n) option remember; if n <= 9 then return 0 fi; 1+procname(convert(convert(n,base,10),`*`)) end proc: select(mp=8, [$1..4000000]); # Robert Israel, Feb 12 2019
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Mathematica
okQ[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&, n,IntegerLength[ #]>1&]]==9; Select[Range[2700000],okQ] (* Harvey P. Dale, Jan 29 2011 *)
Extensions
Offset corrected by Robert Israel, Feb 12 2019