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 A350931 #27 Dec 22 2023 16:37:09 %S A350931 1,1,7,105,2294,71753,3051554,175457984 %N A350931 Maximal determinant of an n X n Toeplitz matrix using the integers 1 to 2*n - 1. %C A350931 Also maximal absolute value of the determinant of an n X n Hankel matrix using the integers 1 to 2*n - 1. - _Stefano Spezia_, Dec 22 2023 %H A350931 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A350930%2B1.py">A350930+1.py</a> %H A350931 Wikipedia, <a href="http://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz Matrix</a> %e A350931 a(2) = 7: %e A350931 [3 1] %e A350931 [2 3] %e A350931 a(3) = 105: %e A350931 [5 1 3] %e A350931 [4 5 1] %e A350931 [2 4 5] %o A350931 (Python) %o A350931 from itertools import permutations %o A350931 from sympy import Matrix %o A350931 def A350931(n): return max(Matrix([p[n-1-i:2*n-1-i] for i in range(n)]).det() for p in permutations(range(1,2*n))) # _Chai Wah Wu_, Jan 27 2022 %Y A350931 Cf. A322908, A323254, A350930 (minimal). %K A350931 nonn,hard,more %O A350931 0,3 %A A350931 _Stefano Spezia_, Jan 25 2022 %E A350931 a(5) from _Alois P. Heinz_, Jan 25 2022 %E A350931 a(6) from _Pontus von Brömssen_, Jan 26 2022 %E A350931 a(7) from _Lucas A. Brown_, Aug 28 2022