OFFSET
0,1
REFERENCES
A. J. Hoffman, On eigenvalues of symmetric (+1, -1) matrices, Israel J. Math., 17 (1974), 69-75 (MR 50#2202).
MATHEMATICA
f[n_]:=Module[{n2n=n^2-n}, 4 (2^(n2n+1) n2n-n+3)]; Array[f, 15] (* Harvey P. Dale, Mar 24 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 24 2003
STATUS
approved