%I
%S 1,1,1,1,1,1,1,1,1,1,0,1,0,0,0,0,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,0,0,0,
%T 0,1,0,0,0,1,0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,0,1,0,0,0,0,0,
%U 0,1,0,1,0,0,0,0,0,0,0,1,1,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,1,1,1,0,1,0,0,1,0,0,1
%N Characteristic function of Niven (or Harshad) numbers.
%C a(A005349(n)) = 1; a(A065877(n)) = 0;
%C also a(A038186(n)) = 1.
%H Reinhard Zumkeller, <a href="/A188641/b188641.txt">Table of n, a(n) for n = 1..10000</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Harshad_number">Harshad number</a>
%H Eric Weisstein, <a href="http://mathworld.wolfram.com/HarshadNumber.html">Harshad Numbers</a>
%F a(n) = A000007(A070635(n)).
%o (Haskell)
%o a188641 = (1 ) . signum . a070635
%Y Cf. A007953, A188642.
%K nonn,base
%O 1
%A _Reinhard Zumkeller_, Apr 07 2011
