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A272658 Number of distinct characteristic polynomials of n X n matrices with elements {-1, 0, +1}. 8
3, 16, 209, 8739, 1839102 (list; graph; refs; listen; history; text; internal format)
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 Brino-Tarasoff, Venkat Balasubramanian.)

LINKS

Table of n, a(n) for n=1..5.

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: A174137 A166860 A196562 * 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

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Last modified October 21 00:56 EDT 2017. Contains 293679 sequences.