The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A055165 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A055165

Number of invertible n X n matrices with entries equal to 0 or 1.
(history; published version)

#46 by Alois P. Heinz at Sat Jun 18 09:49:11 EDT 2022

STATUS

editing

approved

#45 by Alois P. Heinz at Sat Jun 18 09:22:07 EDT 2022

DATA

1, 1, 6, 174, 22560, 12514320, 28836612000, 270345669985440, 10160459763342013440

OFFSET

1,2

0,3

EXTENSIONS

a(0)=1 prepended by Alois P. Heinz, Jun 18 2022

#44 by Alois P. Heinz at Sat Jun 18 09:18:20 EDT 2022

CROSSREFS

Main diagonal of A064230.

STATUS

approved

editing

#43 by Peter Luschny at Sat Sep 25 06:47:28 EDT 2021

STATUS

reviewed

approved

#42 by Joerg Arndt at Sat Sep 25 04:03:14 EDT 2021

STATUS

proposed

reviewed

#41 by Michel Marcus at Fri Sep 24 17:03:40 EDT 2021

STATUS

editing

proposed

#40 by Michel Marcus at Fri Sep 24 17:03:35 EDT 2021

LINKS

Miodrag Zivkovic, <a href="httphttps://arXivarxiv.org/abs/math.CO/0511636">Classification of small (0,1) matrices</a>, arXiv:math/0511636 [math.CO], 2005; Linear Algebra and its Applications, 414 (2006), 310-346.

STATUS

proposed

editing

#39 by Chai Wah Wu at Fri Sep 24 16:52:28 EDT 2021

STATUS

editing

proposed

#38 by Chai Wah Wu at Fri Sep 24 16:51:59 EDT 2021

PROG

(Python)

from itertools import product

from sympy import Matrix

def A055165(n): return sum(1 for s in product([0, 1], repeat=n**2) if Matrix(n, n, s).det() != 0) # Chai Wah Wu, Sep 24 2021

STATUS

approved

editing

#37 by N. J. A. Sloane at Wed Aug 15 22:18:46 EDT 2018

STATUS

proposed

approved