OFFSET
1,2
FORMULA
a(n) = (-1)^(n-1)*(n+1)^2*n^(n-2)*(n^(2n)-b(n)^n-c(n)^n+(n^2+3n+3)^n)/24
where
b(n)=(2*n^2+3*n-3+sqrt(15n^2+18n-9)i)/2 and
c(n)=(2*n^2+3*n-3-sqrt(15n^2+18n-9)i)/2
EXAMPLE
a(3) = 19548 = determinant
|1, 8, 27|
|27, 1, 8|
|8, 27, 1|
MATHEMATICA
f[n_] := Det[ Table[ RotateLeft[ Range@ n^3, -j], {j, 0, n - 1}]]; Array[f, 12] (* Robert G. Wilson v, Aug 31 2014 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Missouri State University Problem-Solving Group (MSUPSG(AT)MissouriState.edu), May 05 2010
STATUS
approved