cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A000410 Number of singular n X n rational (0,1)-matrices.

Original entry on oeis.org

0, 0, 6, 425, 65625, 27894671, 35716401889, 144866174953833
Offset: 1

Views

Author

Keywords

Comments

Number of all n X n (0,1)-matrices having distinct, nonzero ordered rows and determinant 0 - compare A000409.
a(n) is the number of singular n X n rational {0,1}-matrices with no zero rows and with all rows distinct, up to permutation of rows and so a(n) = binomial(2^n-1,n) - A088389(n). Cf. A116506, A116507, A116527, A116532. - Vladeta Jovovic, Apr 03 2006

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Formula

n! * a(n) = A046747(n) - 2^(n^2) + n! * binomial(2^n -1, n).

Extensions

n=7 term from Guenter M. Ziegler (ziegler(AT)math.TU-Berlin.DE)
a(8) from Vladeta Jovovic, Mar 28 2006

A116506 Number of singular n X n rational {0,1}-matrices with no zero rows.

Original entry on oeis.org

0, 3, 169, 28065, 16114831, 33686890209, 262530190180063, 7717643584470877185
Offset: 1

Views

Author

Vladeta Jovovic, Apr 03 2006

Keywords

Crossrefs

Formula

a(n) = A055601(n) - A055165(n).

A116527 Number of singular n X n rational {0,1}-matrices with no zero rows or columns and with all rows distinct and all columns distinct, up to permutation of rows.

Original entry on oeis.org

0, 0, 0, 75, 22365, 13303500, 21058940420, 98692672142610
Offset: 1

Views

Author

Vladeta Jovovic, Apr 03 2006

Keywords

Crossrefs

Formula

a(n) = A094000(n) - A088389(n).
Conjecture: a(n) = A000410(n) - A000409(n-1) for n>1. - Jean-François Alcover, Jan 08 2020
Showing 1-3 of 3 results.