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.

A013588 Smallest positive integer not the determinant of an n X n {0,1}-matrix.

Original entry on oeis.org

2, 2, 3, 4, 6, 10, 19, 41, 103, 269
Offset: 1

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Author

Gerhard R. Paseman (paseman(AT)prado.com)

Keywords

Comments

This majorizes the sequence of maximal determinants only up to the 6th term. It is conjectured that the sequence of maximal determinants majorizes this for all later terms.
The first term needing verification is a(11) >= 739. a(12) = 2173 has been verified by Brent, Orrick, Osborn, and Zimmermann in 2010. Lower bounds for the next terms: a(13) >= 6739, a(14) >= 21278, a(15) >= 69259, a(16) >= 230309. - Hugo Pfoertner, Jan 03 2020
Asymptotically, the sequence is at least exponential as there is an exponential lower bound of a(n) >= 2^n / (201*n) due to Shah 2022. - Rikhav Shah, Jul 09 2025

Examples

			There is no 3 X 3 {0,1}-matrix with determinant 3, as such a matrix must have a row with at least one 0 in it.
		

Crossrefs

Programs

  • Python
    from itertools import product
    from sympy import Matrix
    def A013588(n):
        s, k = set(Matrix(n,n,p).det() for p in product([0,1],repeat=n**2)), 1
        while k in s:
            k += 1
        return k # Chai Wah Wu, Oct 01 2021

Extensions

Extended by William P. Orrick, Jan 12 2006. a(7), a(8) and a(9) computed by Miodrag Zivkovic. a(7) and a(8) independently confirmed by Antonis Charalambides. a(10) computed by William Orrick.