cp's OEIS Frontend

A178788 Characteristic function of numbers having distinct digits in their decimal representation.

%I A178788 #28 Feb 16 2025 08:33:12
%S A178788 1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,
%T A178788 1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,1,
%U A178788 1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,0,0,1,1,1
%N A178788 Characteristic function of numbers having distinct digits in their decimal representation.
%C A178788 a(A010784(n)) = 1; a(A109303(n)) = 0;
%C A178788 first differences of A178787.
%C A178788 a(n) <= A196368(n).
%C A178788 a(n) = 0 for n > 9*9!. - _Hieronymus Fischer_, Feb 02 2013
%H A178788 R. Zumkeller, <a href="/A178788/b178788.txt">Table of n, a(n) for n = 0..10000</a>
%H A178788 Michael De Vlieger, <a href="/A178788/a178788.png">Plot a(n) at (x,y) = (n mod 1000, -floor(n/1000))</a>, n = 1..10^6, where black represents a(n) = 1 and white represents a(n) = 0.
%H A178788 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Digit.html">Digit</a>
%H A178788 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F A178788 a(n) = 0^(A055642(n)-A043537(n)).
%t A178788 lst = {}; Do[If[Select[Tally[IntegerDigits[n]][[All, 2]], # > 1 &] == {}, AppendTo[lst, 1], AppendTo[lst, 0]], {n, 0, 104}]; lst (* _Arkadiusz Wesolowski_, May 10 2012 *)
%o A178788 (Haskell)
%o A178788 import Data.List (nub)
%o A178788 a178788 n = fromEnum $ nub (show n) == show n
%o A178788 -- _Reinhard Zumkeller_, Sep 25 2011
%K A178788 base,nonn
%O A178788 0,1
%A A178788 _Reinhard Zumkeller_, Jun 30 2010