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 A247581 #4 Sep 20 2014 14:26:38 %S A247581 3,6,5,6,13,14,17,54,11,55,25,156,29,31,33,272,109,19,21 %N A247581 Base-20 state complexity of partitioned deterministic finite automaton (PDFA) for the periodic sequence (123...n)*. %H A247581 Klaus Sutner and Sam Tetruashvili, <a href="http://www.cs.cmu.edu/~sutner/papers/auto-seq.pdf">Inferring automatic sequences</a> (see table on the p. 5). %Y A247581 Cf. similar sequences listed in A247566. %K A247581 nonn,more %O A247581 2,1 %A A247581 _Vincenzo Librandi_, Sep 20 2014