OFFSET
0,3
COMMENTS
Number of nilpotent n X n matrices over GF(4).
(-1)^n * resultant of the Chebyshev polynomial of first kind of degree n and Chebyshev polynomial of first kind of degree 2n (cf. A039991). - Benoit Cloitre, Jan 26 2003
a(n) is the number of spanning subgraphs (or equivalently sets of edges) in the n X n grid graph. - Andrew Howroyd, Jan 29 2023
REFERENCES
N. J. Fine and I. N. Herstein, The probability that a matrix be nilpotent, Illinois J. Math., 2 (1958), 499-504.
M. Gerstenhaber, On the number of nilpotent matrices with coefficients in a finite field. Illinois J. Math., Vol. 5 (1961), 330-333.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..40
PROG
(PARI) a(n) = 4^(n^2 - n) \\ Andrew Howroyd, Jan 29 2023
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Stephen G Penrice, Mar 29 2000
EXTENSIONS
More terms from James A. Sellers, Apr 08 2000
STATUS
approved