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 A145644 #24 Sep 08 2022 08:45:38
%S A145644 1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,
%T A145644 100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,
%U A145644 10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100,1,10,100
%N A145644 Cubefree part of 10^n.
%C A145644 Period 3: repeat [1, 10, 100].
%H A145644 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,1).
%F A145644 a(n) = 10^(n mod 3) = A050985(A011557(n)) = A011557(A010872(n)). - _Amiram Eldar_, Feb 14 2021
%F A145644 From _Wesley Ivan Hurt_, Apr 18 2021: (Start)
%F A145644 G.f.: (1+10*x+100*x^2)/(1-x^3).
%F A145644 a(n) = a(n-3). (End)
%t A145644 CubefreePart[n_Integer?Positive] := Times @@ Power @@@ ({#[[1]], Mod[ #[[2]], 3]} & /@ FactorInteger[n]); Table[CubefreePart[10^n], {n, 1, 40}]
%t A145644 PadRight[{}, 50, {1, 10, 100}] (* _Wesley Ivan Hurt_, Apr 18 2021 *)
%o A145644 (Magma) &cat [[1, 10,100]^^30]; // _Wesley Ivan Hurt_, Apr 18 2021
%Y A145644 Cf. A004709, A010872, A011557, A050985, A069705, A145642, A145643.
%K A145644 nonn,easy,less
%O A145644 0,2
%A A145644 _Artur Jasinski_, Oct 15 2008
%E A145644 Offset corrected by _Amiram Eldar_, Feb 14 2021