

A272658


Number of distinct characteristic polynomials of n X n matrices with elements {1, 0, +1}.


9




OFFSET

1,1


REFERENCES

Robert M. Corless, Bohemian Eigenvalues, Talk Presented at Computational Discovery in Mathematics (ACMES 2), University of Western Ontario, May 12 2016. (Talk based on joint work with Steven E. Thornton, Sonia Gupta, Jonathan BrinoTarasoff, Venkat Balasubramanian.)


LINKS

Table of n, a(n) for n=1..5.
Eunice Y. S. Chan, Robert Corless, A new kind of companion matrix, Electronic Journal of Linear Algebra, Volume 32, Article 25, 2017, see p. 335.
Robert M. Corless et al., Bohemian Eigenvalues.


CROSSREFS

Six classes of matrices mentioned in Rob Corless's talk: this sequence, A272659, A272660, A272661, A272662, A272663.
Other properties of this class of matrices: A271570, A271587, A271588.  Steven E. Thornton, Jul 13 2016
Sequence in context: A166860 A196562 A317073 * A113597 A000273 A071897
Adjacent sequences: A272655 A272656 A272657 * A272659 A272660 A272661


KEYWORD

nonn,more,hard


AUTHOR

N. J. A. Sloane, May 15 2016


EXTENSIONS

a(4) found by Daniel Lichtblau, May 13 2016
a(5) found by Daniel Lichtblau and Steven E. Thornton, May 19 2016


STATUS

approved



