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 A217518 #19 Sep 08 2022 08:46:04
%S A217518 13,7,7,12,7,6,13,7,7,12,7,6,13,7,7,12,7,6,13,7,7,12,7,6,13,7,7,12,7,
%T A217518 6,13,7,7,12,7,6,13,7,7,12,7,6,13,7,7,12,7,6,13,7,7,12,7,6,13,7,7,12,
%U A217518 7,6,13,7,7,12,7,6,13,7,7,12,7,6,13
%N A217518 Base-n state complexity of partitioned deterministic finite automaton (PDFA) for the periodic sequence (123456)*.
%H A217518 Klaus Sutner and Sam Tetruashvili, <a href="http://www.cs.cmu.edu/~sutner/papers/auto-seq.pdf ">Inferring automatic sequences</a>
%H A217518 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,1).
%F A217518 Periodic with period length 6.
%F A217518 G.f.: x^2(13 + 7*x + 7*x^2 + 12x^3 + 7x^4 + 6x^5)/((1 - x^6)). - _Vincenzo Librandi_, Nov 18 2012
%t A217518 CoefficientList[Series[(13 + 7*x + 7*x^2 + 12x^3 + 7x^4 + 6x^5)/((1 - x^6)), {x, 0, 30}], x] (* _Vincenzo Librandi_, Nov 18 2012 *)
%t A217518 LinearRecurrence[{0,0,0,0,0,1},{13,7,7,12,7,6},80] (* or *) PadRight[ {},80,{13,7,7,12,7,6}] (* _Harvey P. Dale_, Jul 19 2016 *)
%o A217518 (Magma) &cat[[13, 7, 7, 12, 7, 6]: n in [0..30]]; // _Vincenzo Librandi_, Nov 18 2012
%o A217518 (PARI) a(n)=[7, 6, 13, 7, 7, 12][n%6+1] \\ _Charles R Greathouse IV_, Nov 18 2012
%K A217518 nonn,easy
%O A217518 2,1
%A A217518 _N. J. A. Sloane_, Oct 07 2012