A003433 Hadamard maximal determinant problem: largest determinant of (+1,-1)-matrix of order n. (Formerly M1291)

1, 2, 4, 16, 48, 160, 576, 4096, 14336, 73728, 327680, 2985984, 14929920, 77635584, 418037760, 4294967296, 21474836480, 146028888064, 894426939392, 10240000000000, 59392000000000, 409600000000000

Offset

1,2

Comments

I added the entry for n=22 since this has been proved optimal by Chasiotis et al (reference in A003432). [Richard P. Brent, Aug 17 2021]

References

Ed Hughes and Rob Pratt, New Features in SAS/OR 13.1, SAS Paper SAS256-2014.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

See A003432 for further references, links and formulas.

Links

Table of n, a(n) for n=1..22.

Richard P. Brent and Judy-anne H. Osborn, On minors of maximal determinant matrices, arXiv preprint arXiv:1208.3819 [math.CO], 2012.

Massimiliano Fasi and Gian Maria Negri Porzio, Determinants of Normalized Bohemian Upper Hessemberg Matrices, University of Manchester (England, 2019).

John Holbrook, Nathaniel Johnston, and Jean-Pierre Schoch, Real Schur norms and Hadamard matrices, arXiv:2206.02863 [math.CO], 2022.

Ion Nechita, Some analytical aspects of Hadamard matrices.

William P. Orrick and B. Solomon, Large-determinant sign matrices of order 4k+1, Discr. Math. 307 (2007), 226-236.

Eric Weisstein's World of Mathematics, -11-Matrix

Index entries for sequences related to binary matrices

Index entries for sequences related to Hadamard matrices

Index entries for sequences related to maximal determinants

Formula

a(n) = 2^(n-1)*A003432(n-1). E.g., a(6) = 32*A003432(5) = 32*5 = 160.

a(n) <= n^(n/2).

Mathematica

A003432 = Cases[Import["https://oeis.org/A003432/b003432.txt", "Table"], {_, _}][[All, 2]];
a[n_] := 2^(n-1) A003432[[n]];
a /@ Range[21] (* Jean-François Alcover, Jan 17 2020 *)

Crossrefs

A003432 is the main entry for this sequence.

Cf. A051753.

Cf. A188895 (number of distinct matrices having this maximal determinant).

Sequence in context: A119000 A034917 A215724 * A153951 A248748 A350646

Adjacent sequences: A003430 A003431 A003432 * A003434 A003435 A003436

Keyword

nonn,hard,nice

Author

N. J. A. Sloane

Extensions

a(19)-a(21) added by William P. Orrick, Dec 20 2011

a(22) added by Richard P. Brent, Aug 16 2021

Status

approved