OFFSET
1,2
LINKS
I. Reiner, On the number of matrices with given characteristic polynomial, Illinois J. Math. 5 1961 324-329.
PROG
(PARI) \\ see Reiner reference.
F(u, r)={prod(i=1, r, (1-u^(-i)))}
a(n, q=3)={my(D=ffgen(q)); my(f=factor(D^0*(x^n-1))); q^(n^2-n)*F(q, n)/prod(i=1, #f~, F(q^poldegree(f[i, 1]), f[i, 2]))} \\ Andrew Howroyd, Jul 08 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Yuval Dekel (dekelyuval(AT)hotmail.com) and W. Edwin Clark, Nov 29 2003
EXTENSIONS
Offset corrected and a(9)-a(11) from Andrew Howroyd, Jul 08 2018
STATUS
approved