%I
%S 1,2,2,5,2,5,2,14,6,5,2,23,2,5,5,61,2,26,2,35,5,5,2
%N Number of different sets of parameters for mixed orthogonal arrays with n runs and strength 2.
%D A. S. Hedayat, N. J. A. Sloane and J. Stufken, Orthogonal Arrays, SpringerVerlag, NY, 1999.
%D Eric D. Schoen, Pieter T. Eendebak and Man V. M. Nguyen, Complete enumeration of purelevel and mixedlevel orthogonal arrays, Journal of Combinatorial Designs, Volume 18, Issue 2, pages 123140, March 2010; DOI: 10.1002/jcd.20236; Correction: Journal of Combinatorial Designs, Volume 18, Issue 6, page 488, November 2010; DOI: 10.1002/jcd.20270.
%H E. M. Rains, N. J. A. Sloane and J. Stufken, The Lattice of NRun Orthogonal Arrays, J. Stat. Planning Inference, 102 (2002), 477500 (<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>)
%e For 12 runs there are 23 different sets of parameters: 12^1, 2^k with 1<=k<=11, 3^1*2^k with 0<=k<=4, 6^1*2^k with 0<=k<=2, 4^1*3^1, 4^1 and 1^1.
%Y Cf. A039927, A039930.
%K nonn,nice,more
%O 1,2
%A _N. J. A. Sloane_.
%E Needs to be updated using the results of Schoen et al. (2010).  _N. J. A. Sloane_, Feb 21 2013
%E a(36) is the first unknown term.
