OFFSET
1,1
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
EXAMPLE
26888999 -> [ 4478976 ][ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in nine steps.
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
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
Patrick De Geest, Sep 15 1998
EXTENSIONS
Offset corrected by Robert Israel, Feb 12 2019
STATUS
approved