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 A158863 #5 May 31 2018 11:09:52
%S A158863 4,8,36,32,76,72,124,128,180,200,244,288,316
%N A158863 Maximal excess of a 3-normalized Hadamard matrix of order 4n.
%C A158863 The excess of a {-1,1} matrix is the sum of its elements. A Hadamard matrix is 3-normalized if its first three rows contain an even number of entries -1 in each column. 3-normalized Hadamard matrices of order 4n with large excess can be used to construct large-determinant {-1,1} matrices of order 4n+1.
%H A158863 W. P. Orrick and B. Solomon, <a href="http://www.indiana.edu/~maxdet">The Hadamard Maximal Determinant Problem</a> (website)
%H A158863 W. P. Orrick and B. Solomon, <a href="https://dx.doi.org/10.1016/j.disc.2006.04.041">Large-determinant sign matrices of order 4k+1</a>, Discr. Math. 307 (2007), 226-236.
%Y A158863 Cf. A004118.
%K A158863 hard,more,nonn
%O A158863 1,1
%A A158863 _William P. Orrick_, Mar 28 2009