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 A351821 #8 Mar 16 2022 02:52:33 %S A351821 1,3,7,16,46,138,601,2619,16162,93531,654700,4442304 %N A351821 Maximal sum of inverse squares of the singular values of Toeplitz anti-Hadamard matrices of order n. %H A351821 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, Table 1. %Y A351821 Cf. A005312, A005313, A351240, A351241. %K A351821 nonn,hard,more %O A351821 1,2 %A A351821 _Stefano Spezia_, Feb 20 2022 %E A351821 a(12) confirmed and inserted by _Stefano Spezia_, Mar 16 2022