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 A014262 #28 Feb 19 2018 11:01:01
%S A014262 1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,-1,-1,-1,-1,-1,-1,-1,
%T A014262 -1,-1,-1,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A014262 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A014262 Inverse of 253rd cyclotomic polynomial.
%C A014262 Periodic with period length 253. - _Ray Chandler_, Apr 03 2017
%C A014262 In general the expansion of 1/Phi(N) is N-periodic, but also satisfies a linear recurrence of lower order given by degree(Phi(N)) = phi(N) = A000010(N) < N. The signature is given by the coefficients of (1-Phi(N)). - _M. F. Hasler_, Feb 18 2018
%H A014262 Vincenzo Librandi, <a href="/A014262/b014262.txt">Table of n, a(n) for n = 0..1000</a>
%H A014262 <a href="/index/Rec#order_220">Index entries for linear recurrences with constant coefficients</a>, order 220.
%H A014262 <a href="/index/Pol#poly_cyclo_inv">Index to sequences related to inverse of cyclotomic polynomials</a>
%p A014262 with(numtheory,cyclotomic); c := n->series(1/cyclotomic(n,x),x,80);
%t A014262 CoefficientList[Series[1/Cyclotomic[253, x], {x, 0, 200}], x] (* _Vincenzo Librandi_, Apr 07 2014 *)
%o A014262 (PARI) Vec(1/polcyclo(253)+O(x^99)) \\ _Charles R Greathouse IV_, Mar 24 2014
%Y A014262 Cf. similar sequences listed in A240328, A240467.
%K A014262 sign,easy
%O A014262 0,1
%A A014262 _Simon Plouffe_