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 A374281 #14 Jul 07 2024 05:46:25 %S A374281 1,0,1,8,44,946,27495,592100,25369920,1246207300,55400732937 %N A374281 a(n) is the maximal absolute value of the determinant of an n X n symmetric Toeplitz matrix having 0 on the main diagonal and all the integers 1, 2, ..., n-1 off-diagonal. %H A374281 Wikipedia, <a href="https://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz Matrix</a>. %F A374281 a(n) = max(abs(A374279(n)), A374280(n)). %e A374281 a(5) = 946: %e A374281 [0, 1, 4, 2, 3] %e A374281 [1, 0, 1, 4, 2] %e A374281 [4, 1, 0, 1, 4] %e A374281 [2, 4, 1, 0, 1] %e A374281 [3, 2, 4, 1, 0] %t A374281 a[0]=1; a[n_]:=Max[Table[Abs[Det[ToeplitzMatrix[Join[{0},Part[Permutations[Range[n-1]],i]]]]],{i,(n-1)!}]]; Array[a,11,0] %Y A374281 Cf. A085750, A351609. %Y A374281 Cf. A085807 (minimal permanent), A374279 (minimal), A374280 (maximal), A374282 (minimal nonzero absolute value), A374283 (maximal permanent). %K A374281 nonn,hard,more %O A374281 0,4 %A A374281 _Stefano Spezia_, Jul 02 2024