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A272662 Number of distinct characteristic polynomials of n X n matrices with elements {-1, +1}. 11
2, 6, 28, 203, 3150, 131641 (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..6.

CROSSREFS

Six classes of matrices mentioned in Rob Corless's talk: A272658, A272659, A272660, A272661, A272662, A272663.

Sequence in context: A216187 A178446 A324126 * A125812 A093657 A305627

Adjacent sequences:  A272659 A272660 A272661 * A272663 A272664 A272665

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, May 15 2016

EXTENSIONS

a(5) and a(6) from Steven E. Thornton, Mar 09 2019

STATUS

approved

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Last modified January 27 08:31 EST 2020. Contains 331293 sequences. (Running on oeis4.)