OFFSET
1,2
LINKS
R. L. Graham and N. J. A. Sloane, Anti-Hadamard matrices, Linear Alg. Applic., 62 (1984), 113-137.
FORMULA
Conjectures: (Start)
a(n) = 1 for n > 9.
G.f.: x*(x + x^3 + 2*x^5 + x^8 + 1/(1 - x)). (End)
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Stefano Spezia, Mar 08 2022
STATUS
approved