A091471 Number of n X n matrices with entries {-1,1} that are diagonalizable over the complex numbers.

2, 12, 464, 50224, 25095232

Offset

1,1

Comments

See A091472 for definition of diagonalizable and for Mathematica definitions.

Links

Table of n, a(n) for n=1..5.

Eric Weisstein's World of Mathematics, Diagonalizable Matrix

Index entries for sequences related to binary matrices

Mathematica

Table[Count[Matrices[n, {-1, 1}], _?DiagonalizableQ], {n, 4}]

Prog

(Sage)
import itertools
def a(n):
    ans, W = 0, itertools.product([-1, 1], repeat=n*n)
    for w in W:
        if Matrix(QQbar, n, n, w).is_diagonalizable(): ans += 1
    return ans  # Robin Visser, Sep 27 2023

Crossrefs

Cf. A091470, A091472.

Sequence in context: A350790 A296623 A009510 * A357895 A012625 A012630

Adjacent sequences: A091468 A091469 A091470 * A091472 A091473 A091474

Keyword

nonn,more

Author

Eric W. Weisstein, Jan 12 2004

Extensions

a(5) from Robin Visser, Sep 27 2023

Status

approved