A202022 - OEIS

%I #12 Jun 21 2022 17:26:17

%S 1,1,1,1,1,1,1,1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,

%T 0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,

%U 0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0

%N Characteristic functions of repdigit numbers in decimal representation.

%C a(A010785(n)) = 1; a(A139819(n)) = 0;

%C a(n) = A136522(n) for n <= 100, a(101) = 0, A136522(101) = 1.

%H Reinhard Zumkeller, <a href="/A202022/b202022.txt">Table of n, a(n) for n = 0..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Repdigit.html">Repdigit</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Repdigit">Repdigit</a>

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%F a(n) = if A043537(n) = 1 then 1 else 0. - _Reinhard Zumkeller_, Nov 29 2012

%t Table[If[Count[DigitCount[n],0]==9,1,0],{n,0,120}] (* _Harvey P. Dale_, Jun 21 2022 *)

%o (Haskell)

%o a202022 = fromEnum . (== 1) . a043537

%o -- _Reinhard Zumkeller_, Nov 29 2012, Dec 09 2011

%K nonn,base

%O 0

%A _Reinhard Zumkeller_, Dec 09 2011