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 A253513 #34 Jul 10 2022 09:42:56
%S A253513 1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,
%T A253513 0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,
%U A253513 0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0
%N A253513 The characteristic function of the multiples of eight.
%C A253513 Period 8: repeat [1, 0, 0, 0, 0, 0, 0, 0].
%H A253513 Antti Karttunen, <a href="/A253513/b253513.txt">Table of n, a(n) for n = 0..16384</a>
%H A253513 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,1).
%F A253513 a(n) = floor(n/8) - floor((n-1)/8).
%F A253513 a(n) = sin((sin(Pi*(n+1)/2)^2)*Pi*(n+2)/4)/2 + (sin(Pi*(n+1)/2)^2)/4 + sin(Pi*(n+1)/2)/4.
%F A253513 a(n) = abs(A014025(n)).
%F A253513 From _Alois P. Heinz_, Jan 03 2015: (Start)
%F A253513 a(n) = 1 - A168181(n).
%F A253513 G.f.: 1/(1-x^8). (End)
%t A253513 Table[Boole[IntegerQ[n/8]], {n, 0, 127}] (* _Michael De Vlieger_, Jan 03 2015, after _Alonso del Arte_ at A121262 *)
%t A253513 LinearRecurrence[{0,0,0,0,0,0,0,1},{1,0,0,0,0,0,0,0},120] (* or *) PadRight[ {},120,{1,0,0,0,0,0,0,0}] (* _Harvey P. Dale_, Apr 07 2017 *)
%t A253513 Array[ Boole[ Mod[#, 8] == 0] &, 105, 0] (* _Robert G. Wilson v_, Oct 08 2017 *)
%o A253513 (PARI) A253513(n) = !(n%8); \\ _Antti Karttunen_, Oct 08 2017
%o A253513 (Python)
%o A253513 def A253513(n): return int(not(n&7)) # _Chai Wah Wu_, Jul 09 2022
%Y A253513 Cf. A008590 (multiples of 8), A010877, A014025, A168181, A244413.
%K A253513 nonn,easy
%O A253513 0,1
%A A253513 _Mikael Aaltonen_, Jan 03 2015