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A223474 Least positive multiple of n that when written in base 10 has digits in nonincreasing order.

%I A223474 #12 Mar 26 2013 14:07:22
%S A223474 1,2,3,4,5,6,7,8,9,10,11,60,52,42,30,32,51,54,76,20,21,22,92,72,50,52,
%T A223474 54,84,87,30,31,32,33,442,70,72,74,76,663,40,41,42,43,44,90,92,94,96,
%U A223474 98,50,51,52,53,54,55,840,741,522,531,60,61,62,63,64,65,66,871,544,552,70,71,72,73,74,75,76,77,6552,553,80,81,82,83,84,85
%N A223474 Least positive multiple of n that when written in base 10 has digits in nonincreasing order.
%C A223474 This sequence is well defined (same reasoning as for A079339).
%H A223474 Giovanni Resta, <a href="/A223474/b223474.txt">Table of n, a(n) for n = 1..2000</a>
%e A223474 a(39) = 663 because it is the least multiple of 39 appearing in A009996.
%t A223474 a[n_] := Block[{x=n}, While[0 < Max@Differences@IntegerDigits@x, x += n]; x]; Array[a, 85] (* _Giovanni Resta_, Mar 26 2013 *)
%o A223474 (Perl)
%o A223474 sub A223474 {
%o A223474     my $n = shift;
%o A223474     my $a = $n;
%o A223474     while ($a !~ /^9*8*7*6*5*4*3*2*1*0*$/) {
%o A223474         $a += $n;
%o A223474     }
%o A223474     return $a;
%o A223474 }
%o A223474 foreach (1..100) {
%o A223474     print A223474($_), ",";
%o A223474 }
%Y A223474 a(n)/n yields sequence A223475.
%Y A223474 Cf. A004290, A181060.
%Y A223474 Cf. A009996.
%K A223474 nonn,base
%O A223474 1,2
%A A223474 _Paul Tek_, Mar 20 2013