This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A352177 #15 Dec 13 2023 08:32:56 %S A352177 1,2,1,2,1,3,1,1,2,1,1,1,1,1,1,1,1,1,1 %N A352177 a(n) is the number of symmetric Toeplitz anti-Hadamard matrices of order n whose sum of the inverse squares of their singular values is maximal. %H A352177 R. L. Graham and N. J. A. Sloane, <a href="http://dx.doi.org/10.1016/0024-3795(84)90090-9">Anti-Hadamard matrices</a>, Linear Alg. Applic., 62 (1984), 113-137. %F A352177 Conjectures: (Start) %F A352177 a(n) = 1 for n > 9. %F A352177 G.f.: x*(x + x^3 + 2*x^5 + x^8 + 1/(1 - x)). (End) %Y A352177 Cf. A351240, A351241. %Y A352177 Cf. A005312, A005313, A351821, A351984. %K A352177 nonn,hard,more %O A352177 1,2 %A A352177 _Stefano Spezia_, Mar 08 2022