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 A109338 #4 Mar 30 2012 16:50:18 %S A109338 1,1,1,1,1,1,1,2,2,1,1,2,2,2,1,1,2,4,4,2,1 %N A109338 Triangle read by rows: T(n,k) = number of inequivalent binary sequences of length n and weight k, where two sequences are said to be equivalent if they have the same set of phrases in their Ziv-Lempel encodings (the phrases can appear in a different order in the two sequences). %C A109338 The Ziv-Lempel encoding scans the sequence from left to right and inserts a comma when the current phrase is an extension by one bit of an earlier phrase. In any case the scan ends with a comma. The phrases are the segments between the commas. %C A109338 Equivalent sequences necessarily have the same Hamming weight. %C A109338 See A106182 for further references and links. %D A109338 J. Ziv and A. Lempel, A universal algorithm for sequential data compression. IEEE Trans. Information Theory IT-23 (1977), 337-343. %e A109338 1; 1,1; 1,1,1; 1,2,2,1; 1,2,2,2,1; 1,2,4,4,2,1; ... See A106182 for detailed examples. %Y A109338 Row sums give A106182. %K A109338 nonn,more,tabl %O A109338 1,8 %A A109338 _N. J. A. Sloane_, Aug 24 2005