This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A168185 #29 Sep 23 2018 21:25:34 %S A168185 0,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1, %T A168185 1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1, %U A168185 1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1 %N A168185 Characteristic function of numbers that are not multiples of 12. %C A168185 a(n+12) = a(n); %C A168185 a(n) = A000007(A010881(n)); %C A168185 a(A168186(n)) = 1; a(A008594(n)) = 0; %C A168185 A033444(n) = Sum_{k=0..n} a(k)*(n-k). %H A168185 Antti Karttunen, <a href="/A168185/b168185.txt">Table of n, a(n) for n = 0..65537</a> %H A168185 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a> %H A168185 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,1). %F A168185 For the general case: the characteristic function of numbers that are not multiples of m is a(n) = floor((n-1)/m) - floor(n/m) + 1, m,n > 0. - _Boris Putievskiy_, May 08 2013 %p A168185 a:=n->`if`(modp(n,12)=0,0,1); seq(a(n),n=0..150); # _Muniru A Asiru_, Sep 21 2018 %t A168185 If[Divisible[#,12],0,1]&/@Range[0,120] (* _Harvey P. Dale_, Apr 03 2015 *) %o A168185 (PARI) a(n)=!!(n%12) \\ _Charles R Greathouse IV_, Aug 21 2011 %Y A168185 Cf. A010881, A145568, A168184, A168182, A168181, A109720, A097325, A011558, A166486, A011655, A000035. %K A168185 nonn,easy %O A168185 0,1 %A A168185 _Reinhard Zumkeller_, Nov 30 2009