login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A136609 (1/(n!)^2) * number of ways to arrange the consecutive numbers 1...n^2 in an n X n matrix with determinant = 0. 3
0, 0, 76, 14392910 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The computation of a(5) seems to be currently (Jan 2008) out of reach (compare with A088021(5)).

LINKS

Table of n, a(n) for n=1..4.

EXAMPLE

a(1)=0 because det((1))/=0, a(2)=0, because the only possible determinants of a matrix with elements {1,2,3,4} are +-2, +-5 and +-10.

CROSSREFS

Cf. A001044, A046747, a(3)=A088215(0), a(4)=A136608(0), A221976.

Sequence in context: A222739 A060716 A116255 * A116246 A128670 A225522

Adjacent sequences:  A136606 A136607 A136608 * A136610 A136611 A136612

KEYWORD

hard,more,nonn

AUTHOR

Hugo Pfoertner, Jan 21 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 18 07:26 EDT 2020. Contains 337166 sequences. (Running on oeis4.)