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A271588 Number of matrices with multiple eigenvalues from the set of n X n matrices with elements {-1, 0, +1}. 1
0, 19, 4629, 7171257, 89765448427 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

Steven E. Thornton & Robert M. Corless, The Bohemian Eigenvalue Project, Poster Presented at The International Symposium on Symbolic and Algebraic Computation (ISSAC 2016). Wilfrid Laurier University, July 19-22, 2016.

LINKS

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

GitHub repository for code used to generate this sequence.

CROSSREFS

Number of characteristic polynomials A272658.

Sequence in context: A281820 A213450 A099809 * A233464 A145214 A172662

Adjacent sequences: A271585 A271586 A271587 * A271589 A271590 A271591

KEYWORD

nonn,more,hard

AUTHOR

Steven E. Thornton, Jul 13 2016

STATUS

approved

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Last modified November 27 22:56 EST 2022. Contains 358406 sequences. (Running on oeis4.)