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 A039930 #24 Mar 05 2020 03:17:22 %S A039930 0,1,1,4,1,3,1,9,5,3,1,12,1,3,3,21,1,10,1,20,3,3,1,25,7,3,15,28,1,5,1, %T A039930 42,3,3,3 %N A039930 Height of lattice of parameters of mixed orthogonal arrays with n runs and strength 2. %C A039930 a(36) is the first unknown term. %D A039930 A. S. Hedayat, N. J. A. Sloane and J. Stufken, Orthogonal Arrays, Springer-Verlag, NY, 1999. %H A039930 E. M. Rains, N. J. A. Sloane and J. Stufken, The Lattice of N-Run Orthogonal Arrays, J. Stat. Planning Inference, 102 (2002), 477-500 (<a href="http://neilsloane.com/doc/rao.txt">Abstract</a>, <a href="http://neilsloane.com/doc/rao.pdf">pdf</a>, <a href="http://neilsloane.com/doc/rao.ps">ps</a>). %H A039930 Eric D. Schoen, Pieter T. Eendebak and Man V. M. Nguyen, <a href="https://doi.org/10.1002/jcd.20236">Complete enumeration of pure-level and mixed-level orthogonal arrays</a>, Journal of Combinatorial Designs, Volume 18, Issue 2, pages 123-140, March 2010; DOI: 10.1002/jcd.20236; <a href="https://doi.org/10.1002/jcd.20270">Correction</a>: Journal of Combinatorial Designs, Volume 18, Issue 6, page 488, November 2010; DOI: 10.1002/jcd.20270. %Y A039930 Cf. A039927, A039931, A048638. %K A039930 nonn,nice,more %O A039930 1,4 %A A039930 _N. J. A. Sloane_