OFFSET
1,2
REFERENCES
Warren D. Smith, Posting to the Math Fun Mailing List, August 18, 2012.
LINKS
Lucas A. Brown, A215724.py.
Wikipedia, Toeplitz Matrix
EXAMPLE
a(2) = 2:
1 1
-1 1
a(3) = 4:
1 1 1
-1 1 1
1 -1 1
a(6) = 160
1 -1 1 1 1 1
-1 1 -1 1 1 1
-1 -1 1 -1 1 1
-1 -1 -1 1 -1 1
1 -1 -1 -1 1 -1
1 1 -1 -1 -1 1
MAPLE
a:=proc(n)
local T, b, U, M, d, r;
T:= combinat:-cartprod([seq({-1, 1}, j = 1..2*n-1)]);
b:= 0;
while not T[finished] do
U := T[nextvalue]();
M := LinearAlgebra:-ToeplitzMatrix(U, n);
d:= abs(LinearAlgebra:-Determinant(M)):
if d > b then b := d; end if;
end do;
return b;
end proc:
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
W. Edwin Clark, Aug 22 2012
EXTENSIONS
a(15) from Lucas A. Brown, Sep 06 2022
a(16) from Lucas A. Brown, Nov 03 2022
STATUS
approved