A048638 -id:A048638 - cp's OEIS frontend

A039930 Height of lattice of parameters of mixed orthogonal arrays with n runs and strength 2.

Original entry on oeis.org

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, 42, 3, 3, 3

Offset: 1

N. J. A. Sloane

a(36) is the first unknown term.

A. S. Hedayat, N. J. A. Sloane and J. Stufken, Orthogonal Arrays, Springer-Verlag, NY, 1999.

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 (Abstract, pdf, ps).
Eric D. Schoen, Pieter T. Eendebak and Man V. M. Nguyen, Complete enumeration of pure-level and mixed-level orthogonal arrays, Journal of Combinatorial Designs, Volume 18, Issue 2, pages 123-140, 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.

Cf. A039927, A039931, A048638.

A048164 a(0)=1, a(n+1)=1+(2^(2^n)+1)*a(n).

Original entry on oeis.org

1, 4, 21, 358, 92007, 6029862760, 25898063359598159721, 477734946799221833229035410333259818858, 162564778457687820218065957445498785826947155451688293007128627114802460256107

Offset: 0

N. J. A. Sloane, E. M. Rains

a(n) = height of lattice of orthogonal arrays with 2^2^n runs.

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 (Abstract, pdf, ps)

Cf. A039930, A048638.

RecurrenceTable[{a[0]==1,a[n]==1+(2^(2^(n-1))+1)a[n-1]},a,{n,10}] (* Harvey P. Dale, Dec 13 2013 *)

a(n) converges to nearest integer to c*(2^(2^n)-1), where c = 1.403936827882178... (see A048649).

cp's OEIS Frontend

A039930 Height of lattice of parameters of mixed orthogonal arrays with n runs and strength 2.

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