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Distinct digits of n arranged in decreasing order.
12

%I #26 Nov 24 2022 05:22:16

%S 0,1,2,3,4,5,6,7,8,9,10,1,21,31,41,51,61,71,81,91,20,21,2,32,42,52,62,

%T 72,82,92,30,31,32,3,43,53,63,73,83,93,40,41,42,43,4,54,64,74,84,94,

%U 50,51,52,53,54,5,65,75,85,95,60,61,62,63,64,65,6,76,86

%N Distinct digits of n arranged in decreasing order.

%C a(n) <= 9876543210; a(a(n)) = a(n);

%C A055642(a(n)) <= 10;

%C A055642(a(n)) <= A055642(n), A055642(a(n)) = A055642(n) iff A178788(n) = 1;

%C a(A109303(n)) < A109303(n); a(A009995(n)) = A009995(n); a(A071589(n)) > A071589(n);

%C a(n) = A151949(n) + A180410(n).

%H Reinhard Zumkeller, <a href="/A227362/b227362.txt">Table of n, a(n) for n = 0..10000</a>

%p a:= n-> parse(cat(sort([{convert(n, base, 10)[]}[]], `>`)[])):

%p seq(a(n), n=0..68); # _Alois P. Heinz_, Sep 21 2022

%t f[n_] := FromDigits[Reverse@ Union@ IntegerDigits@ n]; f /@ Range[0, 68] (* _Michael De Vlieger_, Apr 16 2015, corrected by _Robert G. Wilson v_ *)

%o (Haskell)

%o import Data.List (nub, sort)

%o a227362 = read . reverse . sort . nub . show :: Integer -> Integer

%o (PARI) a(n) = {if (n == 0, d = [0], d = digits(n)); eval(subst(Pol(vecsort(d,,12)), x, 10));} \\ _Michel Marcus_, Apr 16 2015

%o (PARI) a(n)=fromdigits(vecsort(digits(n),,12)) \\ _Charles R Greathouse IV_, Apr 16 2015

%o (Python)

%o def A227362(n): return int(''.join(sorted(set(str(n)),reverse=True))) # _Chai Wah Wu_, Nov 23 2022

%Y Cf. A004186, A230959.

%K nonn,base,look

%O 0,3

%A _Reinhard Zumkeller_, Jul 09 2013